[Abstract] The microstructure of the donor and acceptor materials within a bulk heterojunction is critical to the performance of organic solar cells, significantly influencing charge generation, transport, and overall efficiency and stability. Here, we studied the role of the donor[thin space (1/6-em)]:[thin space (1/6-em)]acceptor ratio and the use of additives on the resulting microstructure in films and devices based on PM6[thin space (1/6-em)]:[thin space (1/6-em)]Y6. A detailed study of the resulting structures, mainly by X-ray scattering, indicates that the molecular arrangement leading to higher efficiencies is correlated with the presence of a single, well-mixed phase. In this phase, the diffusion of the Y6 molecules is constrained within the PM6 matrix. Interestingly, this microstructure can be achieved either by tuning the composition or by incorporating a solvent additive. Consequently, either approach can be employed to enhance photovoltaic performance., J. M and E. G-F. acknowledge support from the European Union's Horizon 2020 research and innovation program, H2020-FETOPEN-01-2018-2020 “LION-HEARTED”, grant agreement no. 828984. J. M. thanks MICINN for the grant Ref. PID2021-126243NB-I00 and the European Research Council ERC-CoG with reference 101086805. We also acknowledge Ana Martinez Amesti, technician in Electron Microscopy at UPV/EHU, and the teams of the NCD-SWEET beamline at ALBA synchrotron and the XMaS/BM28 beamline at the European Synchrotron. XMaS is a UK national research facility supported by EPSRC. S. R.-G. is thankful to the Marie Sklodowska-Curie Actions (H2020-MSCA-IF-2020) for grant agreement no. 101025608, IDEAL. The authors also thank the financial support of the Spanish Ministerio de Ciencia, Innovación y Universidades, under Grants PID2021-128924OB-I00, TED2021-131911B-I00, and CEX2019-000917-S in the framework of the Spanish Severo Ochoa Centre of Excellence.

[Abstract] A combinatorial study of the effect of in-mixing of various guests on the
thermoelectric properties of the host workhorse polymer poly[2,5-bis(3-tetradecylthiophen-
2-yl)thieno[3,2-b]thiophene] (PBTTT) is presented. Specifically, the composition and thickness for doped films of PBTTT blended with different polymers are varied. Some blends at guest weight fractions around 10–15% exhibit up to a fivefold increase in power factor compared to the reference material, leading to zT values around 0.1. Spectroscopic analysis
of the charge-transfer species, structural characterization using grazing-incidence
wide-angle X-ray scattering, differential scanning calorimetry, Raman, and atomic force microscopy, and Monte Carlo simulations are employed to determine that the key to improved performance is for the guest to promote long-range electrical connectivity and low disorder, together with similar highest occupied molecular orbital levels for both materials in order to ensure electronic connectivity are combined., The authors acknowledge financial support from the Spanish Ministry of Science and Innovation through the Severo Ochoa’ Program for Centers of Excellence in R&D (No. CEX2019-000917-S) and projects PGC2018-095411- B-I00, PGC2018-094620-A-I00, and MAT2017-90024-P (TANGENTS)-EI/Fondo Europeo de Desarrollo Regional and from the European Research Council (ERC) under Grant Agreements Nos. 648901 and 963954. J.M. thanks Ministerio de Ciencia, Innovación y Universidades for the Ramón y Cajal contract. The authors are thankful to Dr. Agustín Mihi for access and support with the FTIR equipment. The authors acknowledge the European funding (European Regional Development Fund and European Social Fund). The authors thank Andrés Gómez Rodríguez from the Scanning Probe Microscopy Laboratory (ICMAB-CSIC) for a set of fine AFM measurements. GIWAXS experiments were performed at NCD-SWEET beamline at ALBA Synchrotron with the collaboration of ALBA staff. Finally, the authors acknowledge the support of the publication fee by the CSIC Open Access Publication Support Initiative through its Unidad de Recursos de Información Científica para la Investigación (URICI). M.K. thanks the Carl Zeiss Foundation for financial support. G.Z. acknowledges the support from Alexander von Humboldt Foundation

Financiado para publicación en acceso aberto: Universidade da Coruña/CISUG, [Abstract] Organic solar cells incorporating non-fullerene acceptors (NFAs) have reached remarkable power conversion efficiencies of over 18%. Unlike fullerene derivatives, NFAs tend to crystallize from solutions, resulting in bulk heterojunctions that include a crystalline acceptor phase. This must be considered in any morphology-function models. Here, it is confirmed that high-performing solution-processed indacenodithienothiophene-based NFAs, i.e., ITIC and its derivatives ITIC-M, ITIC-2F, and ITIC-Th, exhibit at least two crystalline forms. In addition to highly ordered polymorphs that form at high temperatures, NFAs arrange into a low-temperature metastable phase that is readily promoted via solution processing and leads to the highest device efficiencies. Intriguingly, the low-temperature forms seem to feature a continuous network that favors charge transport despite of a poorly order along the π–π stacking direction. As the optical absorption of the structurally more disordered low-temperature phase can surpass that of the more ordered polymorphs while displaying comparable—or even higher—charge transport properties, it is argued that such a packing structure is an important feature for reaching highest device efficiencies, thus, providing guidelines for future materials design and crystal engineering activities., This work was supported by the Ministerio de Ciencia e Innovacion/FEDER (under Ref. PGC2018-094620-A-I00 and PGC2018-095411-B-I00, CEX2019-000917-S, and PGC2018-095411-B-100) and the Basque Country Government (Ref. PIBA19-0051). S.M. is grateful to POLYMAT for the doctoral scholarship. The authors thank A. Arbe, A. Alonso-Mateo, and L. Hueso for their support and access to characterization tools. The authors also thank the technical and human support provided by SGIker of UPV/EHU and European funding (ERDF and ESF). GIWAXS experiments were performed at BL11 NCD-SWEET beamline at ALBA Synchrotron (Spain) with the collaboration of ALBA staff. J.M and E.F.-G. acknowledge support through the European Union's Horizon 2020 research and innovation program, H2020-FETOPEN 01-2018-2020 (FET-Open Challenging Current Thinking), “LION-HEARTED,” Grant Agreement No. 828984. J.M and N.S. would like to thank the financial support provided by the IONBIKE RISE project, which received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie Grant Agreement No. 823989. N.S., A.K., and A.B. furthermore are grateful to the U.S. National Science Foundation (NSF) for support via Project No. 1905901 within NSF's Division of Materials Research. A.S. and M.C. acknowledge financial support by the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation program “HEROIC,” Grant Agreement No. 638059. This work was partially carried out at Polifab, the micro- and nanotechnology center of the Politecnico di Milano. C.M. thanks the Knut and Alice Wallenberg Foundation for funding through the project “Mastering Morphology for Solution-borne Electronics.” A.I. thanks MICINN for a Personal Técnico de Apoyo contract (PTA2017-14359-I) and gratefully acknowledge the financial support of the Basque Government (Research Groups IT-1175-19) and the MICINN (PGC2018-094548-B-I00, MCIU/AEI/FEDER, UE.
Funding for open access charge: Universidade da Coruña/CISUG., Gobierno Vasco; PIBA19-0051, Gobierno Vasco; IT-1175-19, Estados Unidos. National Science Foundation; 1905901

[Abstract]: Chemical doping of organic semiconductors is an essential enabler for applications in electronic and energy-conversion devices such as thermoelectrics. Here, Lewis-paired complexes are advanced as high-performance dopants that address all the principal drawbacks of conventional dopants in terms of limited electrical conductivity, thermal stability, and generality. The study focuses on the Lewis acid B(C6F5)3 (BCF) and 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4TCNQ) bearing Lewis-basic −CN groups. Due to its high electron affinity, BCF:F4TCNQ dopes an exceptionally wide range of organic semiconductors, over 20 of which are investigated. Complex activation and microstructure control lead to conductivities for poly(3-hexylthiophene) (P3HT) exceeding 300 and 900 S cm–1 for isotropic and chain-oriented films, respectively, resulting in a 10 to 50 times larger thermoelectric power factor compared to those obtained with neat dopants. Moreover, BCF:F4TCNQ-doped P3HT exhibits a 3-fold higher thermal dedoping activation energy compared to that obtained with neat dopants and at least a factor of 10 better operational stability., We thank Martin Kreuzer for extensive support and fruitful discussions at the Alba synchrotron BL01-MIRAS beamline. Jiali Guo and Dr. Edgar Gutierrez are also thanked for their support with the Alba experiments. We also thank Prof. Walter Caseri and Dr Marco D’Elia (Department of Materials, ETH Zürich) for generously contributing samples of poly(phenylene methylene)s as well as the many stimulating discussions. Dr Agustín Mihi (ICMAB-CSIC) is thanked for providing access to the Bruker IR spectrophotometry equipment. This work was financially supported by the European Commission through the Marie Skłodowska-Curie project HORATES (GA- 955837), by the Spanish Ministry of Science and Innovation (MCIN/AEI/10.13039/501100011033) under grants PID2020-119777GB-I00, PID2021-128924OB-I00 and the Severo Ochoa Centres of Excellence Program under grant CEX2019-000917-S (particularly, PALOMA grant within ICMAB’s ‘Frontier Interdisciplinary Projects’ (FIP-2021) Program), and by the Generalitat de Catalunya under grant no. 2017 SGR 1506. The work of PSF has been carried out within the PhD program in Physics of the Universitat Autònoma de Barcelona (UAB). We thank the Centro de Supercomputación de Galicia (CESGA) for the use of their computational resources., Generalitat de Catalunya; 2017-SGR-1506

[Abstract] While it is widely recognized that microstructure plays an important role in the performance of organic photovoltaics (OPV), systematic studies are often challenging, as varying the molecular packing through typical chemical means (such as sidechain tuning) often affects the molecular energy levels, thus preventing a clear correlation. In this work we present the synthesis of three perylene imide (PI) based electron acceptors with almost identical energy levels, but distinct packing tendencies. We confirm our initial hypothesis by measuring solution and solid-state absorption, and cyclic voltammetry as well as characterizing the films by grazing incidence wide angle X-ray scattering (GIWAXS). In a second step, we repeat the characterization of the three materials in blends with two polymer donors, namely PCDTBT or PBDBT, whose energy levels are well aligned with those of the PI acceptors, and which, additionally, exhibit different degrees of structural order. We show how the initial strong difference between acceptors is partially blurred in blends, but still critical. Finally, we correlate our structural data with OPV devices made with the corresponding six blends. Our data suggest that a good donor acceptor marriage should ensure good energy alignment but also exhibit complementary crystallization tendencies of the two components., The authors acknowledge financial support from the Spanish Ministry of Science and Innovation through the Severo Ochoa Program for Centers of Excellence in R&D (No. CEX2019-000917-S), and projects PGC2018-095411-B-I00, PID2019-106268GB-C33 and PID2019-110305GB-I00, as well as the European Commission through the Horizon 2020 Marie Sklodowska-Curie ITN Programme, SEPOMO, Grant Number: 722651, and the UCM (INV.GR.00.1819.10759). E. G. specially acknowledges Comunidad de Madrid and Universidad Complutense de Madrid for a post-doctoral contract (CT20/19-CT21/19/PEJD-2018-POST/IND-8661PAI). M. J. A. N. acknowledges URJC for a post-doctoral contract. R. P. O. and A. H. also acknowledge support from Junta de Andalucía (project UMA18-FEDERJA-080). We acknowledge support of the publication fee by the CSIC Open Access Publication Support Initiative through its Unit of Information Resources for Research (URICI), Universidad Complutense de Madrid; INV.GR.00.1819.10759, Universidad Complutense de Madrid; CT20/19-CT21/19/PEJD-2018-POST/IND-8661PAI, Junta de Andalucía; UMA18-FEDERJA-080

Introduction of chirality in the field of molecular conductors has received increasing interest in recent years in the frame of modulation of the crystal packing, and hence conducting properties, with the number of stereogenic centers and absolute configuration, e.g., racemic or enantiopure forms. Here, we describe the preparation by electrocrystallization of chiral radical cation salts, based on the donors methyl-ethylenedithio-tetrathiafulvalene (Me-EDT-TTF) 1 and ethyl-ethylenedithio-tetrathiafulvalene (Et-EDT-TTF) 2 containing one stereogenic center, with the perchlorate anion. Donor 1 provided the series of crystalline materials [(rac)-1]ClO4, [(S)-1]2ClO4 and [(R)-1]2ClO4, while for donor 2 only the 1:1 salts [(rac)-2]ClO4 and [(R)-2]ClO4 could be prepared as suitable single crystals for X-ray analysis. The enantiopure salts of 1 show b-type packing and metallic conductivity in the high temperature regime, with room temperature conductivity values of 5–10 S cm−1, whereas compound [(rac)-2]ClO4 is a very poor semiconductor. Tight-binding extended Hückel band structure calculations support the metallic conductivity of the enantiopure salts of 1 and suggest that small structural changes, possibly induced by thermal contraction or pressure, could lead to a pseudo-elliptic closed Fermi surface, typical for a 2D metal., This work was supported in France by the CNRS and the University of Angers. The
collaboration between the Portuguese and French team members was also supported by a FCT – French Ministry
of Foreign Affairs bilateral action FCT/PHC-PESSOA 2020-21 (Project 44647UB)., Peer reviewed

The presented work concerns the study of solution sheared organic thin film transistors based on a 2,8-difluoro-5,11-bis(triethylsilylethynyl)anthradithiophene (diF-TES-ADT) polymer blend. Four different polymer binders were tested (i.e., polystyrene 10K and 100K g/mol and poly(methyl methacrylate) 25K and 120K g/mol) in order to investigate the influence of the polymer binder nature and its molecular weight on the thin film morphology and device performance. Structural analysis by X-ray and Raman spectroscopy combined with Atomic Force Microscopy (AFM) and polarized optical microscopy were used for a complete characterization of the thin films. Additionally, resonance Raman spectroscopy elucidated the isomeric composition of the thin film devices and the different interactions of the organic semiconductor with the polymer binders., This work was funded by DGI (Spain) project FANCY CTQ2016-
80030-R and GENESIS PID2019-111682RB-I00, the Generalitat
de Catalunya (2017-SGR-918), and the Spanish Ministry of
Economy and Competitiveness, through the “Severo Ochoa”
Programme for Centers of Excellence in R&D (FUNFUTURE CEX2019-000917-S)). T.S. acknowledges the H2020-MSCACOFUND-2014 Programme (P-SPHERE, Grant agreement
665919). The authors acknowledge the Central European
Research Infrastructure Consortium (CERIC-ERIC) consortium
for the access to experimental facilities at the ElettraSincrotrone Trieste, (Proposal number: 20187028)., Peer reviewed

Two derivatives of [1]benzothieno[3,2-b][1]benzothiophene (BTBT), namely, 2,7-dioctyl-BTBT (C8-BTBT) and 2,7-diphenyl-BTBT (DPh-BTBT), belonging to one of the best performing organic semiconductor (OSC) families, have been employed to investigate the influence of the substitutional side groups on the properties of the interface created when they are in contact with dopant molecules. As a molecular p-dopant, the fluorinated fullerene C60F48 is used because of its adequate electronic levels and its bulky molecular structure. Despite the dissimilarity introduced by the OSC film termination, dopant thin films grown on top adopt the same (111)-oriented FCC crystalline structure in the two cases. However, the early stage distribution of the dopant on each OSC film surface is dramatically influenced by the group side, leading to distinct host–dopant interfacial morphologies that strongly affect the nanoscale local work function. In this context, Kelvin probe force microscopy and photoelectron emission spectroscopy provide a comprehensive picture of the interfacial electronic properties. The extent of charge transfer and energy level alignment between OSCs and dopant are debated in light of the differences in the ionization potential of the OSC in the films, the interface nanomorphology, and the electronic coupling with the substrate., This work has been funded by the Spanish Government through projects PID2019-110907GB-I00, MAT2016-77852-C2-1-R (AEI/FEDER, UE), and the “Severo Ochoa” Programme for Centers of Excellence in R&D (CEX2019-000917-S). We thank the 2017-SGR668 recognition. A.B. thanks the Spanish Government financial support through BES-2016-077519 FPI fellowship. F.S. acknowledges the European Union’s Horizon 2020 Research and Innovation Program under grant agreement no. 730872 and the Marie Skłodowska-Curie grant agreement no. 722651 (SEPOMO project). This work has been carried out within the framework of the doctoral program (PhD) of Material Science (Department of Physics) of the Universitat Autònoma de Barcelona (UAB). O.S. acknowledges the support of the Israel Ministry of Science, the Center for Absorption in Science of the Ministry of Immigrant Absorption, the Committee for Planning and budgeting of the Council for Higher Education under the framework of the KAMEA Program. Y.H.G. is thankful to the Belgian National Fund for Scientific Research (FNRS) for financial support through research projects BTBT no. 2.4565.11, Phasetrans no. T.0058.14, Pi-Fast no. T.0072.18, and 2Dto3D no. 30489208. Financial supports from the French Community of Belgian (ARC no. 20061) are also acknowledged. A.R. acknowledges doctoral fellowship support from the FRIA. We thank the European Synchrotron Radiation Facility (ESRF) for providing access to ID03 for the time of the experiment. We are indebted to G. Sauthier from the ICN2 Photoemission Spectroscopy Facility., Peer reviewed

Lactose intolerance is a pathology caused by lactase enzyme deficiency, usually produced in the intestinal cells provoking symptoms as abdominal pain, bloating, diarrhea, gas and nausea. Gaxilose, 4-O-β-D galactopyranosyl-d-xylose, is used as a diagnostic drug for a non-invasive method for hypolactasia diagnosis. To date, no definitive guide for identifying gaxilose and distinguishing between crystalline forms is available. Data have been collected from a number of different analytical techniques in order to provide a full characterization of the compound and a simple method to discriminate between two solid forms., E. Molins and M. Benito thank to Severo Ochoa FunFuture project (MICINN, CEX2019-917S) and Generalitat de Catalunya (2017SGR1687)., Peer reviewed

Coupling thermoelectrics (TE) with photovoltaics (PV) has emerged as an approach to solid-state solar harvesting, directly converting light and infrared heat into electricity. In this work, we compare PV-TE hybrid devices based on organic semiconductors in three different geometries: a reflection geometry, a non-contact transmission geometry, and a contact transmission geometry. The temperature rises of films of common organic thermoelectric materials, including poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS), single-walled carbon nanotubes (swCNT), and poly[2,5-bis(3-tetradecylthiophen-2-yl)thieno[3,2-b]thiophene] (PBTTT), were measured in configurations representative of the proposed geometries. Because organic semiconductors possess broadband light absorption and low thermal conductivities, a significant rise in temperature was observed under illumination for all geometries. We find, however, that the best configuration is, in fact, the transmission contact mode because it sums two effects. Operating under 1 sun illumination, the temperature of a commercial organic PV module increased by ≈30 K, which leads to an enhancement in OPV performance compared to room temperature. After attaching a thermoelectric to the OPV module, losses from convection are reduced, and the OPV module heats up even more, further increasing its efficiency while additionally enabling thermoelectric generation. Finally, we calculate theoretical thermoelectric efficiencies for the materials and their respective power densities., The authors acknowledge financial support from the Spanish Ministry Science and Innovation through the “Severo Ochoa” Program for Centers of Excellence in R&D SEV-2015-0496 (FUNMAT) and CEX2019-000917-S (FUNFUTURE), and PGC2018-095411-B-I00 (RAINBOW) projects; from the Generalitat de Catalunya through grants 2017SGR488 and AGAUR 2018 PROD 00191; and from the European Research Council (ERC) under grant agreement no. 648901. This project has received funding from the European Union's Horizon 2020 research and innovation program under the Marie Skłodowska-Curie grant agreement no. 713673. J. P. J. has received financial support through the “la Caixa” INPhINIT Fellowship Grant for Doctoral studies at Spanish Research Centers of Excellence (Grant code: LCF/BQ/IN17/11620035), “la Caixa” Banking Foundation (ID100010434), Barcelona, Spain. O. Z. A. acknowledges CONACYT-SENER for his PhD scholarship (no. 472571). J. P. J. acknowledges the departments of Physics, Chemistry and Geology of the Autonomous University of Barcelona (UAB) as coordinators of the PhD programme in Materials Science. The authors thank Dr A. Roig, Dr A. Laromaine and Dr D. Abol-Fotouh (ICMAB-CSIC) for the CNT:cellulose sample preparation and fruitful discussions. The authors thank Dr Aleksandr Perevedentsev for his help with sample preparation, and Mr Pau Molet for his help with the FTIR measurements. We acknowledge support of the publication fee by the CSIC Open Access Publication Support Initiative through its Unit of Information Resources for Research (URICI)., Peer reviewed

A set of mesomorphic materials in which the <i>o</i>-carborane cluster is covalently bonded to a cholesteryl benzoate moiety (mesogen group) through a suitably designed linker is described. The olefin cross-metathesis between appropriately functionalized styrenyl-<i>o</i>-carborane derivatives and a terminal alkenyl cholesteryl benzoate mesogen (all type I terminal olefins) leads to the desired <i>trans</i>-regioisomer, which is the best-suited configuration to obtain mesomorphic properties in the final materials. The introduction of different substituents (R = H (<b>M2</b>), Me (<b>M3</b>), or Ph (<b>M4</b>)) to one of the carbon atoms of the <i>o</i>-carborane cluster (C_cluster) enables the tailoring of liquid crystalline properties. Compounds <b>M2</b> and <b>M3</b> show the chiral nematic (N*) phase, whereas <b>M4</b> do not show liquid crystal behavior. Weaker intermolecular interactions in the solid <b>M3</b> with respect to those in <b>M2</b> may allow the liquid crystallinity in <b>M3</b> to be expressed as enantiotropic behavior, whereas breaking the stronger intermolecular interaction in the solid state of <b>M2</b> leads directly to the isotropic state, resulting in monotropic behavior. Remarkably, <b>M3</b> also displays the blue phase, which was observed neither in the chiral nematic precursor nor in the styrenyl-cholesterol model (<b>M5</b>) without an <i>o</i>-carborane cluster, which suggests that the presence of the cluster plays a role in stabilizing this highly twisted chiral phase. In the carborane-containing mesogens (<b>M2</b> and <b>M3</b>), the <i>o</i>-carborane cluster can be incorporated without destroying the helical organization of the mesophase., This research was funded by MICINN grants (PID2019-106832RB-100 and CEX2019-000917-S) and Generalitat de Catalunya (2017/SGR/1720)., Peer reviewed

Epitaxial orthorhombic Hf0.5Zr0.5O2 (HZO) films on La0.67Sr0.33MnO3 (LSMO) electrodes show robust ferroelectricity, with high polarization, endurance and retention. However, no similar results have been achieved using other perovskite electrodes so far. Here, LSMO and other perovskite electrodes are compared. A small amount of orthorhombic phase and low polarization is found in HZO films grown on La-doped BaSnO3 and Nb-doped SrTiO3, while null amounts of orthorhombic phase and polarization are detected in films on LaNiO3 and SrRuO3. The critical effect of the electrode on the stabilized phases is not consequence of differences in the electrode lattice parameter. The interface is critical, and engineering the HZO bottom interface on just a few monolayers of LSMO permits the stabilization of the orthorhombic phase. Furthermore, while the specific divalent ion (Sr or Ca) in the manganite is not relevant, reducing the La content causes a severe reduction of the amount of orthorhombic phase and the ferroelectric polarization in the HZO film., Financial support from the Spanish Ministry of Science and
Innovation, through the Severo Ochoa FUNFUTURE (CEX2019-
000917-S) and the MAT2017-85232-R (AEI/FEDER, EU), and PID2019-
107727RB-I00 (AEI/FEDER, EU) projects, and from Generalitat de
Catalunya (2017 SGR 1377) is acknowledged. IF and JG acknowledge
Ramón y Cajal contracts RYC-2017-22531 and RYC-2012-11709,
respectively. IF acknowledges Beca Leonardo from Fundación BBVA.
SE acknowledges the Spanish Ministry of Economy, Competitiveness
and Universities for his PhD contract (SEV-2015-0496-16-3) and its
cofunding by the ESF. SE work has been done as a part of his Ph.D.
program in Materials Science at Universitat Autònoma de Barcelona.
Electron microscopy observations carried out at the Centro Nacional
de Microscopía Electrónica at UCM (MV) supported by MICINN
grant# RTI2018-097895-B-C43., Peer reviewed

A carbon-based hybrid nanocomposite, which consists of monoiodinated boron-cluster derivatives covalently attached to graphene oxide, is hereby introduced. This GO-I-COSAN has been synthesized using a novel boron-rich cobaltabis(dicarbollide) precursor with one iodide group attached to one of the boron atoms of the cluster (I-COSAN) and designed to be subsequently labeled with radioactive 124I for its use in positron emission tomography (PET). In vitro cytotoxicity studies of GO-I-COSAN with HeLa cells at different concentrations up to 48 h proved that the cell mortality was lower than 10%, indicating minimal cytotoxicity of the nanomaterial. Remarkably, internalization of the nanomaterial by cells was confirmed by transmission electron microscopy, which indicated its accumulation in the cytoplasm, without causing changes in either the size or morphology of the cells. Additionally, in vivo tests using Caenorhabditis elegans confirmed that GO-I-COSAN could be ingested by the worms, showing no significant damage and very low toxicity, which supports the results observed in the in vitro studies. Radioisotopic labeling of I-COSAN using a palladium-catalyzed isotopic exchange reaction with Na[124I]I and its subsequent functionalization onto GO was performed successfully, leading to formation of the radioactive nanocomposite GO-[124I]I-COSAN, which was quickly injected in mice. PET images at different times revealed excellent in vivo stability of the developed nanomaterial. No activity in thyroid and stomach was observed even at long times, proving that iodide did not detach from the material. GO-[124I]I-COSAN presented a favorable biodistribution profile, being mainly accumulated in the liver and slightly in the lung, with a long residence time on blood and progressive elimination via the gastrointestinal tract. It is noteworthy that the high boron content of this material paves the way toward theranostics because it benefits of a traceable boron delivery for boron neutron capture therapy., This work was supported by the Spanish Ministry of Science
and Innovation MICINN, through the Severo Ochoa Program
for Centers of Excellence FUNFUTURE (CEX2019-000917-
S), for funding with an internal Severo Ochoa FIP project. J.L.
thanks the Spanish Ministry of Economy and Competitiveness
for funding through Grant CTQ2017-87637-R. Part of the
work was conducted under the Maria de Maeztu Units of
Excellence Programme (Grant MDM-2017-0720). A.M.-J. and
A.L. are thankful for financial support from the Spanish
Ministry of Science and Innovation through Project RTI2018-
096273-B-I00 and a Ph.D. scholarship for A.M.J. (FPU18/
05190) and the Generalitat de Catalunya with Projects
2017SGR765 and 2017SGR581. A.M.-J. and A.L. participated
in the MICINN, “Research Networks” nanoCARE (RED2018-
102469-T). This work has been conducted within the
Biotechnology Doctoral Program of the Autonomous University of Barcelona (A.M.J). The authors thank the staff from
the Servei de Cultius Cel·lulars and Servei de Microscopia, ̀
both at the UAB, for performing the cytotoxicity studies,
cellular uptake analysis, and HRTEM., Peer reviewed

Micro- and nanoscale patterned monolayers of plasmonic nanoparticles were fabricated by combining concepts from colloidal chemistry, self-assembly, and subtractive soft lithography. Leveraging chemical interactions between the capping ligands of pre-synthesized gold colloids and a polydimethylsiloxane stamp, we demonstrated patterning gold nanoparticles over centimeter-scale areas with a variety of micro- and nanoscale geometries, including islands, lines, and chiral structures (e.g., square spirals). By successfully achieving nanoscale manipulation over a wide range of substrates and patterns, we established a powerful and straightforward strategy, nanoparticle chemical lift-off lithography (NP-CLL), for the economical and scalable fabrication of functional plasmonic materials with colloidal nanoparticles as building blocks, offering a transformative solution for designing next-generation plasmonic technologies., The authors would like to thank the Nanoquim clean room facility at ICMAB-CSIC and, in particular, Dr. Luigi Morrone for help with the use of the microwriter for master preparation. We acknowledge the CNSI-EICN, ICMAB-CSIC, and ICN2 electron microscopy facilities for TEM and SEM imaging, WiTEC for access to their microscopy instrumentation, and Dr. Thomas Young and Michael Mellody for the preparation of silicon masters. Special thanks to Dr. Leonora Velleman for the fruitful discussion on nanoparticle self-assembly. L.S. research is supported by the Marie Sklodowska-Curie Actions SHINE (H2020-MSCA-IF-2019, grant agreement No. 894847) and the 2020 Post-doctoral Junior Leader-Incoming Fellowship by “la Caixa” Foundation (ID 100010434, fellowship code LCF/BQ/PI20/11760028). L.A.P. thanks the Marie Sklodowska-Curie Actions (H2020-MSCA-IF-2018) for grant agreement No. 839402, PLASMIONICO. L.S., L.A.P., C.D., and A.M. acknowledge funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program (Grant Agreement No. 637116, ENLIGHTMENT). ICMAB acknowledges the Spanish Ministry of Economy and Competitiveness under grants PID2019-106860GB-I00 (AEI/FEDER, UE) and FUNFUTURE (CEX2019-000917-S) center of excellence Severo Ochoa program. This work has been performed in the framework of the doctorate in Materials Science of the Autonomous University of Barcelona. N.C. thanks the NIH NIBIB Pathway to Independence Award (K99EB028325) for support. S.J.J. is supported by the NIH Common Fund through a NIH Director’s Early Independence Award co-funded by the National Institute of Dental and Craniofacial Research and Office of the Director, NIH Grant DP5OD028181. S.J.J. also acknowledges Young Investigator Award funds from the Alex’s Lemonade Stand Foundation for Childhood Cancer Research and the Hyundai Hope on Wheels Foundation for Pediatric Cancer Research. P.S.W. thanks the National Science Foundation (2004238) for support of this work. Funds for core facility use were provided via a support voucher awarded to N.C. and S.J.J. via the UCLA Clinical and Translational Science Institute (CTSI) Core Voucher Program, which is administered through Grant Number UL1TR001881., Peer reviewed

Self‐propelled particles and, in particular, those based on mesoporous silica, have raised considerable interest due to their potential applications in the environmental and biomedical fields thanks to their biocompatibility, tunable surface chemistry and large porosity. Although spherical particles have been widely used to fabricate nano‐ and micromotors, not much attention has been paid to other geometries, such as nanorods. Here, we report the fabrication of self‐propelled mesoporous silica nanorods (MSNRs) that move by the catalytic decomposition of hydrogen peroxide by a sputtered Pt layer, Fe2O3 nanoparticles grown within the mesopores, or the synergistic combination of both. We show that motion can occur in two distinct sub‐populations characterized by two different motion dynamics, namely enhanced diffusion or directional propulsion, especially when both catalysts are used. These results open up the possibility of using MSNRs as chassis for the fabrication of self‐propelled particles for the environmental or biomedical fields., R.M. thanks “la Caixa” Foundation through IBEC International PhD Programme “la Caixa” Severo Ochoa fellowships (code LCF/BQ/SO16/52270018). A.C.H. thanks MINECO for the Severo Ochoa PhD fellowship. J.G. has received financial support through the “la Caixa” INPhINIT Fellowship Grant for Doctoral Studies at Spanish Research Centers of Excellence (Grant code: LCF/BQ/DI17/11620041), “la Caixa” Banking Foundation (ID100010434), Barcelona, Spain. The CERCA program by the Generalitat de Catalunya, the Secretaria d′Universitats i Recerca del Departament d′Empresa i Coneixement de la Generalitat de Catalunya through the projects 2017SGR1148 & 2017SGR765 are acknowledged, as well as the Ministerio de Ciencia, Innovación y Universidades (MCIU)/Agencia Estatal de Investigación (AEI)/Fondo Europeo de Desarrollo Regional (FEDER, UE) through the projects RTI2018‐098164‐B‐I00 & RTI2018‐096273‐B‐I00 and Severo Ochoa Programme for Centres of Excellence in R&D (CEX2019‐000917‐S and CEX2018‐000789‐S). This project has received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (grant agreement No 866348)., Peer reviewed

During the last decades, nanoparticles (NPs) have been widely used in various fields, especially in medical applications such as drugs, imaging agents, and drug-delivery carriers. However, they also raised public concerns regarding the potential adverse influences on human health. Collective efforts from worldwide researchers in materials and biological science have been invested in investigating the toxicity mechanisms of different NPs.
In this thesis, we dedicated major efforts to apply (Caenorhabditis elegans) C. elegans as a robust and simple model organism for toxicity assessments of assorted NPs. The general objective of this thesis was to study effects of food availability on nano-bio interactions between superparamagnetic iron oxide nanoparticles (SPIONs) or 10 nm AuNPs and C. elegans, and prove that this small animal can be used to study alimentary effects.
Firstly, we studied the effects of food availability on toxicities induced by exposure to SPIONs after 24 h (acute exposure) or 72 h (prolonged exposure). We found that food provided some protection to C. elegans determined by measuring multiple toxicity endpoints such as survival and reproduction. Worms in the acute exposure condition had a higher uptake efficiency of SPIONS facilitated by food compared with the condition without the addition of food. The utilization of synchrotron Fourier transform infrared microspectroscopy (SR-μFTIR), allowed us to demonstrate that long-exposure (24 h versus 4 h) and high concentrations of SPIONs (500 μg/mL versus 100 μg/mL) induce more severe oxidative stress determined by increased levels of lipid oxidation.
Secondly, we investigated food’s influences on worms after 24 h exposure to 10 nm AuNPs. The protective role of food was identified in reducing toxic effects, such as survival and reproduction. Using SR-μFTIR, we found that small-sized AuNPs (10 nm versus 150 nm) or long-exposure (24 h versus 4 h) caused an increased level of lipid oxidation which was related to responses against oxidative stress. On the other hand, we preliminarily evaluated the possibility of performing the photothermal therapy in worms containing 150 nm AuNPs. We found photoablated damages on the laser irradiation spots of worms, suggesting that multiple experimental settings needed to be optimized.
At the end of the thesis, also we presented some collaborations where we performed some experiments with different nanomaterials such as lutein and (metal-organic frameworks) MOFs and evaluated them on C. elegans. We studied antioxidative properties of lutein in C. elegans disease models associated with Leigh Syndrome and demonstrated the possibility to apply synchrotron Fourier transform infrared microspectroscopy (SR-μFTIR) on this topic. On the other hand, we performed the preliminary toxicity assessment of MOFs, MIL-127 and chitosan (CS) coated MIL-127 (CS-MIL-127). Additionally, we investigated about effects of the chitosan (CS) coating on C. elegans’ uptake and excretion efficiencies of MIL-127 and CS-MIL-127. We reported the potential of applying C. elegans as an oral administration model of studying metal-organic frameworks’ (MOFs’) in vivo toxicities.
In summary, food availability could decrease adverse effects, partially associated with oxidative stress, induce by SPIONs or AuNPs on C. elegans. It also suggested that C. elegans has a great potential of being employed as an oral administration model of testing various materials. Furthermore, combined with other advanced techniques, we could have a more general understanding of the toxicity mechanism and broaden the application range of material science techniques for biological research., Finally, I acknowledge the funding from the Chinese Scholarship Council for pursuing my PhD degree., With funding from the Spanish government through the ‘Severo Ochoa Centre of Excellence’
accreditation (CEX2019-000917-S)., No

The annealing process is an important step common to epitaxial films prepared by chemical solution deposition methods. It is so because the final microstructure of the films can be severely affected by the precise features of the thermal processing. In this work we analyze the structural and magnetic properties of double perovskite La2CoMnO6 and La2NiMnO6 epitaxial thin films prepared by polymer-assisted deposition (PAD) and crystallized by rapid thermal annealing (RTA). It is found that samples prepared by RTA have similar values of saturation magnetization and Curie temperature to their counterparts prepared by using conventional thermal annealing (CTA) processes, thus indicating low influence of the heating rates on the B-B’ site cationic ordering of the A2BB’O6 double perovskite structure. However, a deeper analysis of the magnetic behavior suggested some differences in the actual microstructure of the films., This research was founded by the Spanish Ministry of Science, Innovation and
Universities through Severo Ochoa (SEV-2015–04969) and Severo Ochoa FUNFUTURE (CEX2019-000917-S),
SUMATE (RTI2018-095853-B-C21), and SPIN-CURIOX (RTI2018-099960- B-100) projects co-financed by the
European Regional Development Fund. Hailin Wang acknowledges financial support from the China Scholarship
Council (CSC). This work has been performed in the framework of the Ph.D. program in Materials Science of the
Universitat Autònoma de Barcelona (UAB), through the CSC/UAB Joint Scholarship., Peer reviewed

Many charge density wave (CDW) systems exhibit q(T ) electron-hole modulations continuously varying with
T and saturating upon cooling at an incommensurate value even if the maximum occurring in the electron-hole
Lindhard response does not exhibit such a thermal shift. Using a simple RPA argument we show that the
experimental q(T ) can be understood if the electron-phonon coupling (EPC) g(q), necessary to set coupled
electronic and structural modulations, is momentum dependent. In this analysis, the sense of variation of
q(T ) depends upon the sign of ∂g(q)
∂q and its amplitude of thermal variation is controlled by the electron-hole
coherence length (or CDW rigidity) in the modulation direction. This model quantitatively accounts for the
thermal dependence of q(T ) in the one-dimensional (1D) CDW system K0.3MoO3 (blue bronze) both in its CDW
ground state and in its pretransitional CDW fluctuation regime. We suggest that such a general analysis can be
extended to account for the q(T ) dependence observed in other 1D and 2D CDW systems such as the transition
metal di- and trichalcogenides as well as the lanthanide and rare-earth tritellurides. Using a detailed analysis of
the low frequency phonon spectrum of the blue bronze, we then propose a new scenario for the q dependent
EPC, where g(q) is due to a momentum-dependent hybridization between the critical phonon branch bearing the
Kohn anomaly and other low-lying phonon branches. This allows obtaining a sign of ∂g(q)
∂q in agreement with that
deduced from the analysis of q(T ). Finally, we propose that similar hybridization effects could also be relevant
for other 1D and 2D CDW systems exhibiting a thermally dependent modulation., This work was supported by Spanish MICIU through Grant
No. PGC2018-096955-B-C44 and the Severo Ochoa FUNFUTURE (CEX2019-000917-S) Excellence Centre distinction,
and Generalitat de Catalunya (Grant No. 2017SGR1506)., Peer reviewed

Control over the energy level alignment in molecular junctions is notoriously difficult, making it challenging to control basic electronic functions such as the direction of rectification. Therefore, alternative approaches to control electronic functions in molecular junctions are needed. This paper describes switching of the direction of rectification by changing the bottom electrode material M = Ag, Au, or Pt in M–S(CH2)11S–BTTF//EGaIn junctions based on self-assembled monolayers incorporating benzotetrathiafulvalene (BTTF) with EGaIn (eutectic alloy of Ga and In) as the top electrode. The stability of the junctions is determined by the choice of the bottom electrode, which, in turn, determines the maximum applied bias window, and the mechanism of rectification is dominated by the energy levels centered on the BTTF units. The energy level alignments of the three junctions are similar because of Fermi level pinning induced by charge transfer at the metal–thiolate interface and by a varying degree of additional charge transfer between BTTF and the metal. Density functional theory calculations show that the amount of electron transfer from M to the lowest unoccupied molecular orbital (LUMO) of BTTF follows the order Ag > Au > Pt. Junctions with Ag electrodes are the least stable and can only withstand an applied bias of ±1.0 V. As a result, no molecular orbitals can fall in the applied bias window, and the junctions do not rectify. The junction stability increases for M = Au, and the highest occupied molecular orbital (HOMO) dominates charge transport at a positive bias resulting in a positive rectification ratio of 83 at ±1.5 V. The junctions are very stable for M = Pt, but now the LUMO dominates charge transport at a negative bias resulting in a negative rectification ratio of 912 at ±2.5 V. Thus, the limitations of Fermi level pinning can be bypassed by a judicious choice of the bottom electrode material, making it possible to access selectively HOMO- or LUMO-based charge transport and, as shown here, associated reversal of rectification., The authors express thanks to the Ministry of Education
(MOE) for supporting this research under award nos.
MOE2018-T2-1-088 and R-143-000-B30-112. We also acknowledge the Prime Minister’s Office, Singapore, under its
Medium Sized Centre program for supporting this research.
This work was also funded by ITN iSwitch 642196, the DGI
(Spain), projects FANCY (CTQ2016-80030-RA), GENESIS
(PID2019-111682RB-I00) and MOTHER (MAT2016-80826-
R), the Generalitat de Catalunya (2017-SGR-918), the
Instituto de Salud Carlos III, through “Acciones CIBER”,
and the Spanish Ministry of Economy and Competitiveness
through the “Severo Ochoa” program for Centers of Excellence
in R&D (FUNFUTURE; CEX2019-000917-S). The work in
Mons was financially supported by the EC through the Marie Curie project ITN iSwitch (GA no. 642196). Computational
resources were provided by the Consortium des É
quipements
de Calcul Intensif (CÉ
CI) funded by the Belgian National
Fund for Scientific Research (F.R.S.-FNRS) under grant
2.5020.11. J.C. is an FNRS research director., Peer reviewed

Novel composite materials are being investigated for improving the energy storage performance of electrochemical capacitors. For this goal, synergistic effects via the combination of diverse types of materials are crucial. In this work, electrodes composed of reduced graphene oxide, multiwall carbon nanotubes, as well as cerium and manganese oxides were fabricated through reactive inverse matrix-assisted pulsed laser evaporation (RIMAPLE). UV-pulsed laser irradiation of frozen aqueous dispersions containing graphene oxide sheets, carbon nanotubes, and ceria nanoentities, besides manganese acetate precursor, led to the simultaneous chemical transformation and co-deposition of hybrid electrodes onto flexible metallic substrates via photothermal and photochemical processes. Thorough morphological and compositional studies of the electrodes demonstrated the laser-induced reduction of graphene oxide, besides the crystallization of a mixture of cerium and manganese oxide nanostructures decorating the carbon nanoentities during the deposition process. Electrochemical analyses revealed a remarkable improvement of performance with the combination of electrochemical double layer in the porous nanocarbon framework with pseudocapacitance from the oxide nanostructures, obtaining excellent volumetric capacitances of up to 140 F cm−3 at 10 mV s−1 with the combination of all four materials. The attained results are the best ones yet published regarding RIMAPLE of hybrid nanocarbon-based electrodes with micrometric thickness. Finally, symmetric electrochemical capacitors were fabricated using aqueous electrolyte, revealing excellent stability upon tens of thousands of charge–discharge cycles., The authors thank the financial support of the Spanish Ministry of Economy, Industry and Competitiveness under the project ENE2017-89210-C2-1-R and support from AGAUR of Generalitat de Catalunya through projects 2017 SGR 1086 and 2017 SGR 1771. PGL thanks the financial support of the Spanish Ministry of Economy, Industry and Competitiveness through the grant BES-2017-081652 for the formation of scientific researchers. ICMAB acknowledges financial support from the Spanish Ministry of Economy and Competitiveness, through Severo Ochoa FUNFUTURE (CEX2019-000917-S). The FTIRM experiments were performed at MIRAS beamline at ALBA Synchrotron with the collaboration of ALBA staff. We acknowledge support of the publication fee by the CSIC Open Access Publication Support Initiative through its Unit of Information Resources for Research (URICI)., Peer reviewed

The intrinsic mobile interfaces in ferroelectrics—the domain walls can drive and enhance diverse ferroelectric properties, essential for modern applications. Control over the motion of domain walls is of high practical importance. Here we analyse theoretically and show experimentally epitaxial ferroelectric films, where mobile domain walls coexist and interact with immobile growth-induced interfaces—columnar boundaries. Whereas these boundaries do not disturb the long-range crystal order, they affect the behaviour of domain walls in a peculiar selective manner. The columnar boundaries substantially modify the behaviour of non-ferroelastic domains walls, but have negligible impact on the ferroelastic ones. The results suggest that introduction of immobile boundaries into ferroelectric films is a viable method to modify domain structures and dynamic responses at nano-scale that may serve to functionalization of a broader range of ferroelectric films where columnar boundaries naturally appear as a result of the 3D growth., The authors are grateful to Prof. A. Gruverman for useful discussions. Marijke Spanjer is acknowledged for proofreading the manuscript. PY acknowledges the Russian Foundation for Basic Research, Grant No. 19-02-00938. The study of the interaction of ferroelastic DWs with CBs was carried out under a state contract with IT SB RAS. KS acknowledges the support by the French Government "Investments for the Future" Program, University of Bordeaux Initiative of Excellence (IDEX Bordeaux), and by the Generalitat de Catalunya (Grant No. 2017SGR 1506). PY, AD and MT acknowledge the Operational Program Research, Development and Education, financed by the European Structural and Investment Funds and the Czech Ministry of Education, Youth, and Sports (Project No. SOLID21, CZ.02.1.01/0.0/0.0/16_019/0000760). MT acknowledges support from the Czech Science Foundation (Grant No. 19-09671S). JP acknowledges the funding from the Academy of Finland (Grant No. 298409)., Peer reviewed

Triple-negative breast cancer (TNBC) is a type of highly aggressive cancer that is hard to be cured by the commonly used chemotherapy, mainly due to the lack of effective tumor targeting ability of the current drugs and TNBC drug resistance. Therefore, development of novel strategies for precise and high-efficient therapy of TNBCs is urgently needed. In the present work, a multifunctional magnetic gold nanoheterostructure with photosensitizer Ce6 loading (MGN@Ce6) was designed and synthesized for synergistic photothermal and photodynamic therapy (PTT/PDT) of TNBC. To improve the tumor targeting ability, cRGD and TPP cationic molecule, which can specifically target αvβ3 integrin of cancer cell membrane and mitochondria, respectively, were functionalized on the nanosystem obtaining MGN@Ce6@RT. In vitro and in vivo fluorescent imaging demonstrated that cRGD and TPP functionalization largely enhanced the delivery-efficiency of MGN@Ce6@RT into TNBC cells and tumors. Under 880 nm and 660 nm laser irradiations, MGN@Ce6@RT exhibited strong hyperthermia effect and ROS generating ability, which exerted a synergistic anti-TNBC effect by completely suppressed the tumor growth of the nude mice model. Moreover, by integrating superparamagnetic and near infrared light absorption properties into a single nanocomposite, MGN@Ce6@RT was proved to be able to realize magnetic resonance, X-ray computed tomography and photoacoustic tri-modal imaging of in vivo tumors. In all, we provide a novel strategy for precise delivery of functional nanosystems to TNBC tumors to achieve more satisfying treating outcome., B. Li performed experiment, collected and interpreted the data, and wrote the draft version of the manuscript. Q. Zhou carried out the rat experiment, histology and cytotoxicity analysis. H.Y. Wang did some of the in vivo multimodal imaging parts. Y.C. Zha did some of the characterizations. P.L. Zheng helped some in vitro cell experiments. Y. Hu synthesized MGN@Ce6@RT. L. Qiu helped the in vivo CT imaging performance and imaging data analysis. T. Yang participated in flow experiments. X.M. Xu designed the graphical abstract and scheme picture. A. Roig helped in the analysis of the MRI data and editing the manuscript. D. Ma, S.M. Yu and W. Xue provided the funding. W. Xue discussed the results and corrected the manuscript. S.M. Yu designed the work, collected the data, discussed the results and corrected the manuscript. We also thank Prof. Peng Huang of Shenzhen University (Guangdong, China) for providing the photoacoustic imaging test service. This work was supported by the China Postdoctoral Science Foundation (2019 M653286), the National Natural Science Foundation of China (31870943, 31900953), the Science and Technology Project of Guangdong Province (2018A050506019), the Natural Science Foundation of Guangdong Province (2018A030313462, 2017A030310297), Guangzhou basic and applied basic research project (202002030002), the Pearl River talent program of Guangdong Province (Youth top-notch talent, 2017GC010330) and the Guangdong Provincial Key Laboratory of Construction and Detection in Tissue Engineering., Peer reviewed

Limbal stem cells (LSCs) are already used in cell‐based treatments for ocular surface disorders. Clinical translation of LSCs‐based therapies critically depends on the successful delivery, survival, and retention of these therapeutic cells to the desired region. Such a major bottleneck could be overcome by using an appropriate carrier to provide anchoring sites and structural support to LSC culture and transplantation. Bacterial nanocellulose (BNC) is an appealing, yet unexplored, candidate for this application because of its biocompatibility, animal‐free origin and mechanical stability. Here, BNC as a vehicle for human embryonic stem cells‐derived LSC (hESC‐LSC) are investigated. To enhance cell‐biomaterial interactions, a plasma activation followed by a Collagen IV and Laminin coating of the BNC substrates is implemented. This surface functionalization with human extracellular matrix proteins greatly improved the attachment and survival of hESC‐LSC without compromising the flexible, robust and semi‐transparent nature of the BNC. The surface characteristics of the BNC substrates are described and a preliminary ex vivo test in simulated transplantation scenarios is provided. Importantly, it is shown that hESC‐LSC retain their self‐renewal and stemness characteristics up to 21 days on BNC substrates. These results open the door for future research on hESC‐LSC/BNC constructs to treat severe ocular surface pathologies., This collaborative project was mainly funded with an european molecular biology organization short‐term fellowship (ref 8288) awarded to I.A.‐S. and the authors would like to express their gratitude to this institution. Researchers acknowledge financial support from the Spanish Ministry of Science and Innovation through the RTI2018‐096273‐B‐I00 project, the Severo Ochoa Programme for Centres of Excellence in R&D (SEV‐2015‐0496 and CEX2019‐000917‐S) and the Ph.D. scholarship of I.A.‐S. (BE‐2017‐076734) as well as Academy of Finland (326760). The authors are also grateful to Generalitat de Catalunya for the 2017SGR765 and the 2019LLAV00046 projects. Authors also appreciate Miquel Anton for his assistance with photography, the AFM service of ICMAB, the electron microscopy facility of ICN2, and the optical microscope service of UAB. The ICMAB members (I.A.‐S., A.L., and A.R.) participate in the CSIC Interdisciplinary Platform for Sustainable Plastics toward a Circular Economy, SUSPLAST, MICINN: “Research Networks” nanoCARE, (RED2018‐102469‐T) and in the Aerogels COST ACTION (CA 18125). This work was conducted within the Material Science Doctoral Program of the Autonomous University of Barcelona (I.A.‐S.). The authors deeply thank the laboratory staff of Tampere University, especially Outi Melin and Hanna Pekkanen for the production, maintenance and differentiation of the hESCs and hESC‐LSC, and Juha Heikkilä for the help with the plasma equipment. The authors acknowledge the Biocenter Finland (BF) and Tampere Imaging Facility (TIF) for their service., Peer reviewed

About ten years after ferroelectricity was first reported in doped HfO2 polycrystalline films, there
is tremendous interest in this material and ferroelectric oxides are once again in the spotlight of
the memories industry. Great efforts are being made to understand and control ferroelectric
properties. Epitaxial films, which have fewer defects and a more controlled microstructure than
polycrystalline films, can be very useful for this purpose. Epitaxial films of ferroelectric HfO2 have
been much less investigated, but after the first report in 2015 significant progress has been
achieved. This review summarizes and discusses the main advances on epitaxial HfO2,
considering growth, study of structural and ferroelectric properties, identification of the
ferroelectric phase, and fabrication of devices. We hope this review will help to researchers
investigating epitaxial HfO2. It can also help extend the interest of the ferroelectric HfO2
community, now basically focused on polycrystalline samples, to epitaxial films., Financial support from the Spanish Ministry of Science and Innovation, through the Severo Ochoa FUNFUTURE (CEX2019-000917-S), MAT2017-85232-R (AEI/FEDER, EU), PID2020-112548RB-I00 (AEI/FEDER, EU), and PID2019-107727RB-I00 (AEI/FEDER, EU) projects, from CSIC through the i-LINK (LINKA20338) program, and from Generalitat de Catalunya (2017 SGR 1377) is acknowledged. Project support was also provided by a 2020 Leonardo Grant for Researchers and Cultural Creators, BBVA Foundation. I.F. acknowledges Ramón y Cajal Contract RYC-2017-22531., Peer reviewed

Combinatorial and high-throughput experimentation (HTE) is achieving more relevance in material design,
representing a turning point in the process of accelerated discovery,
development, and optimization of materials based on data-driven
approaches. The versatility of drop-on-demand inkjet printing
(IJP) allows performing combinatorial studies through fabrication
of compositionally graded materials with high spatial precision,
here by mixing superconducting REBCO precursor solutions with
different rare earth (RE) elements. The homogeneity of
combinatorial Y1−xGdxBa2Cu3O7 samples was designed with
computational methods and confirmed by energy-dispersive Xray spectroscopy (EDX) and high-resolution X-ray diffraction
(XRD). We reveal the advantages of this strategy in the
optimization of the epitaxial growth of high-temperature REBCO superconducting films using the novel transient liquid-assisted
growth method (TLAG). Advanced characterization methods, such as in situ synchrotron growth experiments, are tailored to suit
the combinatorial approach and demonstrated to be essential for HTE schemes. The experimental strategy presented is key for the
attainment of large datasets for the implementation of machine learning backed material design frameworks., The authors acknowledge the European Research Council for the ULTRASUPERTAPE project (ERC-2014-ADG-669504) and EU COST action for CA16218 (NANOCOHYBRI). We also acknowledge financial support from the Spanish Ministry of Economy and Competitiveness, and Spanish Ministry of Science, Innovation and Universities through the “Severo Ochoa” Program for Centers of Excellence in R&D (SEV-2015-0496 and CEX2019-000917-S), SUMATE project (RTI2018-095853-B-C21, co-financed by the European Regional Development Fund). Synchrotron SOLEIL is acknowledged for granting the beamtime (under project no. 20190274) and P. Joly for setup assistance at the DiffAbs beamline. We also acknowledge support from the Catalan Government with 2017-SGR-1519 and the energy Catalan network E4S. A.Q. thanks the Spanish Ministry of Science, Innovation and Universities for his “Juan de la Cierva” postdoctoral fellowship (Grant no. IJC2018-035034-I). We acknowledge support of the publication fee by the CSIC Open Access Publication Support Initiative through its Unit of Information Resources for Research (URICI)., Peer reviewed

Aqueous rechargeable lithium-ion batteries have attracted great attention as an alternative to traditional battery technologies, being able to overcome the issues caused by flammable and expensive organic electrolytes. In particular, LiMn2O4 has reached very fast second-level charge capability by the synthesis of unconventional morphology and particle sizes, allowing charging rates up to 600 C and 93% retention of the capacity after 10,000 cycles. However, the self-discharge process and aging mechanisms for aqueous batteries have been rarely studied, which contrasts with the extensive bibliography of the same phenomena in LMO cells based on organic electrolytes. In this article, the mechanisms involved in the loss of reversible specific charges were studied by diverse techniques like OCV, EIS, and In-situ Raman. The results revealed a more favorable self-discharge process compared with using organic electrolytes owing to the lower stability of water. The self-discharge process can be divided into three different regions with a sequential lower decay rate of voltage and capacity as well as two different evolutions of the electric parameters. This study opens new questions about the nature, composition, and mechanisms of the self-discharge in aqueous media which will play a critical role in the electrochemical performance of novel aqueous Li-ion batteries., This work has been funded by the FP7-NMP-2013-SMALL-7, SiNERGY (Contract 604169), CERCA Programme/Generalitat de Catalunya. A.S., MSCA grant agreement No. 658057 and European Research Council (ERC, grant agreement number 772579). We greatly thank these entities for their economical support as well as the support of the Severo Ochoa FUNFUTURE (CEX2019-000917-S) Exellence Centre distinction., Peer reviewed

In the Jaca foreland basin (southern Pyrenees), two main sediment routing systems merge from the late Eocene to the early Miocene, providing an excellent example of interaction of different source areas with distinct petrographic signatures. An axially drained fluvial system, with its source area located in the eastern Central Pyrenees, is progressively replaced by a transverse-drained system that leads to the recycling of the older turbiditic foredeep. Aiming to provide new insights into the source-area evolution of the Jaca foreland basin, we provide new data on heavy-mineral suites, from the turbiditic underfilled stage to the youngest alluvial-fan systems of the Jaca basin, and integrate the heavy-mineral signatures with available sandstone petrography. Our results show a dominance of the ultrastable Ap-Zrn-Tur-Rt assemblage through the entire basin evolution. However, a late alluvial sedimentation stage brings an increase in other more unstable heavy minerals, pointing to specific source areas belonging to the Axial and the North Pyrenean Zone and providing new insights into the response of the heavy-mineral suites to sediment recycling. Furthermore, we assess the degree of diagenetic overprint vs. provenance signals and infer that the loss of unstable heavy minerals due intrastratal dissolution is negligible at least in the Peña Oroel and San Juan de la Peña sections. Finally, we provide new evidence to the idea that during the late Eocene the water divide of the transverse drainage system was located in the North Pyrenean Zone, and areas constituted by the Paleozoic basement were exposed in the west-Central Pyrenees at that time. Our findings provide new insights into the heavy-mineral response in recycled foreland basins adjacent to fold-and-thrust belts., This paper is a contribution to the projects CGL2014-54180-P and PGC2018-093903-B-C21,
financed by the Ministerio de Economia y Competitividad (MINECO) and Ministerio de Ciencia,
Inovación y Universidades (MCIU) of Spain. X. Coll acknowledges support from the Ministerio de
Cultura, Deporte y Educacción (MCDE) of Spain (FPU grant). We are very grateful to the reviewers Eric Lasseur and Sergio Andò, and to the editor John Southard, for providing constructive reviews that helped to improve the original paper., Peer reviewed

Compositional engineering of BiFeO3 can significantly boost its photovoltaic performance. Therefore, controlling site substitution and understanding how it affects the optical and electronic properties while achieving robust and stable phases is essential to continue progressing in this field. Here the influence of cation co-substitution in BiFeO3 on phase purity, optical and electronic properties is investigated by means of X-ray diffraction, spectroscopic ellipsometry and X-ray absorption spectroscopy, respectively. Piezoelectric force microscopy and ferroelectric characterization at room temperature has been carried out in co-doped BiFeO3 films. First-principles calculations are also performed and compared to the experimental observations. It is shown that the incorporation of La3+ in Bi(Fe,Co)O3 films improves phase purity and stability while preserving the reduced band gap achieved in metastable Bi(Fe,Co)O3. Moreover, it is suggested that the changes in the optoelectronic properties are mainly dictated by the hybridisation between unoccupied Co 3d and O 2p states along with the presence of Co3+/Co2+ species. This thorough study on (Bi,La)(Fe,Co)O3 thin films coupled with the use of a cost-effective and facile solution deposition synthesis increases the motivation to continue exploiting the potential of these perovskite materials., This research was supported by the Spanish Ministerio de Ciencia, Innovación y Universidades (“Severo Ochoa” Programme for Centres of Excellence in R&D CEX2019-000917-S, MAT2017-83169-R, RTI2018-093996-B-C32, PID2019-107727RB-I00 (AEI/FEDER, EU)). P. M. thanks financial support from FPI fellowship (PRE2018-084618). C. M. and C. C. acknowledge computational resources and technical assistance from the Australian Government and the Government of Western Australia through the National Computational Infrastructure (NCI) and Magnus under the National Computational Merit Allocation Scheme and The Pawsey Supercomputing Centre. The authors acknowledge Prof. J. Fontcuberta for providing access to his experimental facilities and the support of ALBA staff for the successful performance of the measurements at CIRCE beamline of the ALBA Synchrotron Light Source. I. F. and C. C. acknowledge support from the Spanish Ministry of Science, Innovation and Universities under the “Ramón y Cajal” fellowship RYC2017-226531 and RYC2018-024947-I, respectively. M. C and I. F acknowledge Beca Leonardo from fundación BBVA. H. T is financially supported by China Scholarship Council (CSC) with no. 201906050014. The work of P. M. and H. T have been done in the framework of the doctorate in Materials Science of the Autonomous University of Barcelona., Peer reviewed

The growth of epitaxial complex oxides has been essentially limited to specific substrates that can induce epitaxial growth and stand high temperature thermal treatments. These restrictions hinder the opportunity to manipulate and integrate such materials into new artificial heterostructures including the use of polymeric and silicon substrates and study emergent phenomena for novel applications. To tackle this bottleneck, herein, a facile chemical route to prepare water‐soluble epitaxial Sr3Al2O6 thin films to be used as sacrificial layer for future free‐standing epitaxial complex oxide manipulation is described. Two solution processes are put forward based on metal nitrate and metalorganic precursors to prepare dense, homogeneous and epitaxial Sr3Al2O6 thin films that can be easily etched by milli‐Q water. Moreover, as a proof of concept, a basic heterostructure consisting of Al2O3/Sr3Al2O6 on SrTiO3 is fabricated to subsequently exfoliate the Al2O3 thin film and transfer it to a polymer substrate. This is a robust chemical and low‐cost methodology that could be adopted to prepare a wide variety of thin films to fabricate artificial heterostructures to go beyond the traditional electronic, spintronic, and energy storage and conversion devices., This research was supported by the Spanish Ministerio de Ciencia, Innovación y Universidades (“Severo Ochoa” Programme for Centres of Excellence in R&D FUNFUTURE CEX2019‐000917‐S and MAT2017‐83169‐R(AEI/FEDER, EU)). The project that gave rise to these results received the support of a fellowship from “la Caixa” Foundation LCF/BQ/DI19/11730026. M.C. acknowledges Becas Leonardo fundación BBVA. I.C. acknowledges the JAE Intro fellowship, JAEINT1901918. This work was done in the framework of the doctorate in material science of the Autonomous University of Barcelona. This work received financial support from the National Key R&D Program of China (2018YFA0305800), and the Beijing Outstanding Young Scientist Program (BJJWZYJH01201914430039)., Peer reviewed

The growth of complex oxide thin films with atomic precision offers bright prospects to study improved properties and novel functionalities. Here we tackle the fabrication of gadolinium iron oxide thin films by an atomic layer deposition-type approach in which iron and gadolinium tailor-made metalorganic precursors (bis(N-isopropyl ketoiminate)iron(II), [Fe(ipki)2] and tris(N,N′-diisopropyl-2-dimethylamido-guanidinato)gadolinium(III), [Gd(DPDMG)3]) are alternately reacted with ozone and deposited on silicon substrates at 250 °C. The structure, chemical composition and magnetic properties of the resulting films are compared with those obtained from a commercially available ferrocene precursor [Fe(Cp)2] and [Gd(DPDMG)3]. All films resulted in cation ratio close to nominal stoichiometry with negligible amount of organic species. The tailor-made metalorganic precursors, designed to provide similar thermal behavior, result in the formation of polycrystalline Gd3Fe5O12 films coexisting with GdFeO3, Gd2O3 and Fe2O3 whereas the combination of [Fe(Cp)2] and [Gd(DPDMG)3] mainly favors the formation of Gd3Fe5O12 films coexisting with traces of Gd2O3. This study demonstrates that this is a viable route to prepare complex GdxFeyOz films and could be used for the design of complex oxide films with improved properties upon rigorous study of the compatibility of metalorganic precursors., This work has been supported through the “Severo Ochoa” Programme for Centres of Excellence in R & D (CEX2019-000917-S), and MAT2017-83169-R from the Spanish Ministry of Economy and Competitiveness. This article is based upon work from COST Action MP1402 “Hooking together European research in atomic layer deposition (HERALD)”, supported by COST (European Cooperation in Science and Technology). The authors gratefully thank the Scientific Services at ICMAB and G. Sauthier from ICN2 core support facilities for XPS analysis. This work has been done in the framework of the doctorate in Materials Science of the Autonomous University of Barcelona. We also acknowledge financial support from China Scholarship Council fellowship to P. Yu (201606920073). The authors from RUB thank the DFG-DE-790-11-1 project for partly supporting this project. M. C. acknowledges Beca Leonardo from Fundación BBVA., Peer reviewed

In the quest for energy efficient and fast memory elements, optically controlled ferroelectric memories are promising candidates. Here, we show that, by taking advantage of the imprint electric field existing in the nanometric BaTiO3 films and their photovoltaic response at visible light, the polarization of suitably written domains can be reversed under illumination. We exploit this effect to trigger and measure the associate change of resistance in tunnel devices. We show that engineering the device structure by inserting an auxiliary dielectric layer, the electroresistance increases by a factor near 2 × 103%, and a robust electric and optic cycling of the device can be obtained mimicking the operation of a memory device under dual control of light and electric fields., Financial support from the Spanish Ministry of Science, Innovation and Universities, through the “Severo Ochoa” Program for Centres of Excellence in R&D (FUNFUTURE, CEX2019-000917-S) and the MAT2017-85232-R (AEI/FEDER, EU), MAT2015-73839-JIN (MINECO/FEDER, EU), PID2019-107727RB-I00 (MINECO/FEDER, EU) projects, and from Generalitat de Catalunya (2017 SGR 1377) is acknowledged. I.F. acknowledges RyC Contract RYC-2017-22531 and Beca Leonardo from Fundación BBVA. X.L and H.T are financially supported by China Scholarship Council (CSC), respectively with nos. 201806100207 and 201906050014. The work of X.L. and H.T. have been done as a part of their Ph.D. program in Materials Science at Universitat Autònoma de Barcelona. We are extremely thankful to R. Solanas for his skillful operation of the PLD system. R. Silvestre-Anglada is acknowledged for assistance in I(V) characteristics fittings., Peer reviewed

The development of advanced piezoelectric α‐quartz microelectromechanical system (MEMS) for sensing and precise frequency control applications requires the nanostructuration and on‐chip integration of this material on silicon material. However, the current quartz manufacturing methods are based on bonding bulk micromachined crystals on silicon, which limits the size, the performance, the integration cost, and the scalability of quartz microdevices. Here, chemical solution deposition, soft‐nanoimprint lithography, and top‐down microfabrication processes are combined to develop the first nanostructured epitaxial (100)α‐quartz/(100)Si piezoelectric cantilevers. The coherent Si/quartz interface and film thinness combined with a controlled nanostructuration on silicon–insulator–silicon technology substrates provide high force and mass sensitivity while preserving the mechanical quality factor of the microelectromechanical systems. This work proves that biocompatible nanostructured epitaxial piezoelectric α‐quartz‐based MEMS on silicon can be engineered at low cost by combining soft‐chemistry and top‐down lithographic techniques., This project had received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (project SENSiSOFT No.803004). L.P. acknowledges the ATIP–Avenir program for financial support. The authors thank C. André for providing the transfected HT1080 cell line and C. Cazevielle (MRI‐COMET, Montpellier) for assistance with biological SEM images. The authors thank D. Montero for performing the FEG–SEM images and chemical analysis. The FEG–SEM instrumentation was facilitated by the Institut des Matériaux de Paris Centre (Grant No. IMPC FR2482) and was funded by Sorbonne Université, CNRS and by the C'Nano projects of the Région Ile‐de‐France. The authors thank Frederic Pichot, David Bourrier, and Guilhem Larrieu for the expertise and advice during the cantilever lithographic processes. The authors also thank Wioletta Trzpil, Frank Augereau, and Eric Rosenkrantz for the advice during vibrometry measurements. A.G and M.G acknowledge funding from the Spanish Ministerio de Ciencia e Innovacion through the severo Ochoa program (CEX2019‐000917‐S)., Peer reviewed

Physical mixtures (i. e. blends) of two or more active materials are often used in commercial batteries to achieve better performance than what can be attained with a single component. This approach has been empirically driven and found to result in relevant synergistic improvements that are unfortunately poorly understood at a fundamental level. Indeed, internal redox processes (which induce structural changes in the components) can take place in blended electrodes that are severely influenced by electrode kinetics. These are in turn affected by temperature and also electrode formulation. Despite difficulties ahead, efforts to understand such issues are needed to pave the way for a rational electrode design enabling optimized performance which ideally could be tuned to match specific application requirements., Authors are grateful to ALISTORE‐ERI colleagues for helpful discussions. ICMAB‐CSIC members thank the Spanish Ministry for Economy, Industry and Competitiveness Severo Ochoa Programme for Centres of Excellence in R&D (CEX2019‐000917‐S) and funding through grant MAT2017‐86616‐R. MCC is also grateful to Spanish Ministry for Economy, Industry and Competitiveness for funding through grant PID2019‐107106RB‐C33., Peer reviewed

Energy-dependent full field transmission soft X-ray microscopy (TXM) is able to give a full picture at the nanometer scale of the chemical state and spatial distribution of oxygen and other elements relevant for battery materials, providing pixel-by-pixel absorption spectrum. We show different methods to localize chemical inhomogeneities in Li1.2Mn0.56Ni0.16Co0.08O2 particles with and without VOx coating extracted from electrodes at different states of charge. Considering the 3d(Mn,Ni)-2p(O) hybridization, it has been possible to discriminate the chemical state of Mn and Ni in addition to the one of O. Different oxidation states correspond to specific features in the O-K spectra. To localize sample regions with specific compositions we apply two different methods. In the first, the pixel-by-pixel ratios of images collected at different key energies clearly highlight local inhomogeneities. In the second, introduced here for the first time, we directly correlate corresponding pixels of the two images on a xy scatter plot that we call phase map, where we can visualize the distributions as function of thickness as well as absorption artifacts. We can select groups of pixels, and then map regions with similar spectral features. Core-shell distributions of composition are clearly shown in these samples. The coating appears in part to frustrate some of the usual chemical evolution. In addition, we could directly observe several further aspects, such as: distribution of conducting carbon; inhomogeneous state of charge within the electrode; molecular oxygen profiles within a particle. The latter suggests a surface loss with respect to the bulk but an accumulation layer at intermediate depth that could be assigned to retained O2., This research was funded by Spanish Government, through the “Severo Ochoa” Programme for Centers of Excellence in R&D (FUNFUTURE CEX2019-000917-S), and the projects
MAT2017-91404-EXP, RTI2018-096273-B-I00 and RTI2018-097753-B-I00 with FEDER cofunding. D.T.
participates in the FLOWBAT 2021 platforms promoted by the Spanish National Research Council
(CSIC). The HIU authors acknowledge the basic funding from the Helmholtz Association., Peer reviewed

High-performing superconducting YBa2Cu3O7–x (YBCO) films are fabricated by a chemical solution deposition methodology through novel barium-deficient low-fluorine solutions. The precursor solutions, distinguished for being straightforward, inexpensive and eco-friendly, allow us to reduce the growing temperature of YBCO down to 750 °C. We investigated the influence of the growing temperatures on both the microstructure and superconducting properties of YBCO films by using conventional thermal annealing and flash-heating approaches. A clear correlation between the growing temperature (Tg) and the superconducting performance of the films was obtained with improved performances observed at low Tg., This work has been carried out within the framework of the EUROfusion Consortium and has received funding from the Euratom Research and Training Programme 2014–2018 and 2019–2020 under grant agreement No 633053. The views and opinions expressed herein do not necessarily reflect those of the European Commission. We acknowledge financial support from Spanish Ministry of Economy and Competitiveness through the Severo Ochoa Programme for Centres of Excellence in R&D (SEV-2015-0496, FUNFUTURE CEX2019-000917-S), SUMATE project RTI2018-095853-B-C21, cofinanced by the European Regional Development Fund, COST-Nanocohybri CA16218 and Catalan Government with 2017-SGR-1519 and XRE4S., Peer reviewed

Peer reviewed

We report here a structural study of RBaMn2O6 (R = La, Pr, and Nd) compounds by means of synchrotron
radiation x-ray powder diffraction and Raman spectroscopy. The three compounds are A-site ordered perovskites
adopting the prototypical tetragonal structure at high temperature. A ferromagnetic transition is observed in the
LaBaMn2O6 sample and the lattice parameters undergo anisotropic changes at TC related to the orientation of
the magnetic moments. Both PrBaMn2O6 and NdBaMn2O6 have a structural transition coupled to an electronic
localization and an antiferromagnetic transition. In both cases, the x-ray diffraction patterns reveal that the lowtemperature phase is orthorhombic with lattice parameters a + b, b − a, and c with respect to the tetragonal
phase. Two possible solutions belonging to the space groups Pmam and P21am can yield accurate refinements of
the x-ray patterns. However, the active modes in the low-temperature phase disclosed by the Raman spectroscopy
clearly point to the noncentrosymmetric space group, P21am. The symmetry analysis of this transition unveils
that the primary modes belong to the irreducible representations M5− and GM5− and the main distortions
correspond to rotations of the MnO6 octahedra and an asymmetric combination of stretching and scissoring
modes of the basal oxygens in these octahedra. We conclude that the low-temperature phase is polar and the main
contribution comes from the displacement of oxygen atoms from their centrosymmetric positions. However,
negligible contribution from the asymmetric stretching associated with a Jahn-Teller distortion is found in this
structural transition, suggesting the lack of ferroic orbital ordering of eg (3dx2−y2 ) orbitals in the orthorhombic ab
plane. There is only one inequivalent site for the Mn atom in the low-temperature polar phase so charge ordering
cannot account for the electronic localization having a structural origin., The authors would like to acknowledge the Servicio
General de Apoyo a la Investigación from Universidad de
Zaragoza. Granted beam time at ALBA synchrotron is appreciated (Proposal No. 2018093038). For financial support,
we thank the Spanish Ministerio de Ciencia, Innovación
y Universidades (Projects No. RTI2018-098537-B-C22 and
No. RTI2018-098537-B-C21 cofunded by ERDF from EU,
and Severo Ochoa FUNFUTURE, CEX2019-000917-S) and
Diputación General de Aragón (Project No. E12-20R)., Peer reviewed

Heteroleptic ruthenium (II) complexes were used for sensitizing ZnO surfaces in organic solar cells (OSCs) as mediators with photoactive layers. The complexes [Ru(4,4′-X2-bpy)(Mebpy-CN)2]2+ (with X = −CH3, −OCH3 and −N(CH3)2; bpy = 2,2′-bipyridine; Mebpy-CN = 4-methyl-2,2′-bipyridine-4′-carbonitrile) were synthesized and studied by analytical and spectroscopical techniques. Spectroscopic, photophysical, and electrochemical properties were tuned by changing the electron-donating ability of the -X substituents at the 4,4′-positions of the bpy ring and rationalized by quantum mechanical calculations. These complexes were attached through nitrile groups to ZnO as interfacial layer in an OSC device with a PBDB-T:ITIC photoactive layer. This modified inorganic electron transport layer generates enhancement in photoconversion of the solar cells, reaching up to a 23% increase with respect to the unsensitized OSCs. The introduction of these dyes suppresses some degradative reactions of the nonfullerene acceptor due to the photocatalytic activity of zinc oxide, which was maintained stable for about 11 months. Improving OSC efficiencies and stabilities can thus be achieved by a judicious combination of new inorganic and organic materials., The authors thank CONICET (Grant PIP-2015-098),
FONCyT (Grant PICT-2016-0553), and UNT (Grant
PIUNT 26D/620) for financial support. F.F.S. thanks
CONICET for a graduate fellowship. N.C.V., M.T., D.C.,
F.E.M.V., M.C., and N.E.K. are Members of the Research
Career (CONICET). J.P.J. and M.C.Q. acknowledge financial
support from the Spanish Ministry Science and Innovation
through the “Severo Ochoa” Program for Centers of Excellence
in R&D SEV-2015-0496 (FUNMAT) and CEX2019-000917-S
(FUNFUTURE) and PGC2018-095411-B-I00 (RAINBOW)
projects. This project received funding from the European
Union’s Horizon 2020 research and innovation program under
the Marie Skłodowska-Curie grant agreement no. 713673. J.P.J.
received financial support through the “la Caixa” INPhINIT
Fellowship Grant for Doctoral studies at Spanish Research
Centers of Excellence (Grant code: LCF/BQ/IN17/
11620035), “la Caixa” Banking Foundation (ID100010434),
Barcelona, Spain., Peer reviewed

Nickel(II) bis(dithiolene) complexes can provide crystalline conducting materials either in their monoanionic or neutral forms. Here we show that the use of chiral dithiolene ligands with one or two stereogenic centres, together with variation of the counter-ion in the anionic complexes, represents a powerful strategy to modulate the conducting properties of such molecular materials. The chiral ligands 5-methyl-5,6-dihydro-1,4-dithiin-2,3-dithiolate (me-dddt) and 5,6-dimethyl-5,6-dihydro-1,4-dithiin-2,3-dithiolate (dm-dddt) have been generated from the thione precursors 1 and 2 which have been structurally and chiroptically characterized. Anionic Ni(II) complexes of these two ligands with tetrabutyl-ammonium (TBA) and tetramethyl-ammonium (TMA) have been prepared and structurally characterized, suggesting that it is the nature of the counter-ion which mostly influences the solid state organization of the complexes. Both TBA and TMA radical anion salts are Mott insulators with antiferromagnetic ground state, as suggested by spin polarized DFT band structure calculations. However, the TMA salts are one order of magnitude more conducting than the TBA counterparts. The neutral materials [Ni(me-dddt)2] and [Ni(dm-dddt)2] are direct band gap semiconductors, as determined by DFT and extended Hückel band structure calculations, with their conductivity drastically increased up to 0.05–3.3 S cm−1 under the highest applied pressures of 10–11 GPa. At equivalent applied pressures the dm-dddt materials are more conducting than the me-dddt ones, in agreement with the lower calculated activation energy and larger bands dispersion for the former. This trend follows the structural change when going from one to two methyl substituents, since the packing and intermolecular interactions are completely different between [Ni(dm-dddt)2] and [Ni(me-dddt)2], the packing of the latter being related to the one of the achiral parent [Ni(dddt)2]. Subtle differences of conductivity are also observed within both series of neutral complexes between the enantiopure and racemic forms. This represents the first series of chiral nickel bis(dithiolene) complexes which shows modulation of the conducting properties with the number of stereogenic centres, the conductivity, measured on single crystals, strongly increasing upon applying hydrostatic pressure., This work was supported in France by the National Agency for Research (ANR, Project 15-CE29-0006-01 ChiraMolCo), the CNRS and the University of Angers. Laurent Veyre (CPE Lyon, France) is gratefully acknowledged for technical help with the synthesis of precursor (rac)-2. Work in Spain was supported by MICIU (Spain) through Grants PGC2018-096955-B-C44 and PGC2018-093863-B-C22, and by Generalitat de Catalunya (2017SGR1506 and 2017SGR1289). E. C. acknowledges support of the Spanish MICIU through the Severo Ochoa FUNFUTURE (CEX2019-000917-S) Excellence Centre distinction and P. A. from the Maria de Maeztu Units of Excellence Program (MDM-2017-0767). The work in Japan was supported by JSPS KAKENHI (Grants No. 16H06346)., Peer reviewed

The local structural and electronical transformations occurring along the first charge and discharge cycle of Li- and Mn-rich Li[Li0.2Ni0.16Mn0.56Co0.08]O2 cathode material have been characterized by X-ray absorption spectroscopy at several complementary edges. The irreversible spinel formation, occurring at the expenses of the cycling layered phase during the first charge, is quantified (about 10%) and spatially localized. The local strains induced by the Ni oxidation have been evaluated. They induce the formation of a low spin Mn3+ in the layered structure in parallel to the irreversible formation of the spinel phase in the particles bulk. The charge balance has been quantified for all the elements along the first charging cycle, confirming a reversible oxygen oxidation along the charge. Overall, these quantitative results provide an experimental basis for modeling aimed to control the structure and its evolution, for instance, hindering the spinel formation for the benefit of the material cycle life., This research was supported by the Spanish Government, through the “Severo Ochoa” Programme for Centers of Excellence in R&D (FUNFUTURE CEX2019-000917-S), and the projects MAT2017-91404-EXP, RTI2018-096273-B-I00, and RTI2018-097753-B-I00 with FEDER cofunding. D.T. participates in the FLOWBAT 2021 platforms promoted by the Spanish National Research Council (CSIC). The HIU authors acknowledge the basic funding from the Helmholtz Association., Peer reviewed

We present herein a systematic study of solvent co-intercalation during electrochemical reduction of titanium disulfide in lithium cells using state of the art in situ cells and synchrotron X-ray diffraction. To understand the role of the electrolyte components, four salts (LiBF4, LiBOB, LiPF6 and LiTFSI) and three solvents (ethylene carbonate, propylene carbonate and dimethyl carbonate) were investigated. Various types of in situ cells were assembled and X-ray diffraction patterns were collected in operando upon cycling. Co-intercalated phase formation was found to be triggered by the presence of propylene carbonate and to be electrochemically driven. This co-intercalated phase is formed in the early stages of reduction, with cell parameters a = 3.514 Å, c = 17.931 Å, corresponding approximately to a tripling of the pristine TiS2 cell along the c-axis. This phase does not seem to evolve upon further oxidation and hence induces an overall loss of capacity. Whereas the nature of the anion does not appear to influence the co-intercalated phase formation, the content of propylene carbonate in the electrolyte is clearly correlated to both its amount and the extent of capacity loss., The authors acknowledge funding from Ministry of Science and Innovation through grant MAT2017–86616-R, from the "Severo Ochoa" Programme for Centres of Excellence in R&D (CEX2019-000917-S). This project has received funding from the European Union's Horizon 2020 research and innovation program under the Marie Skłodowska-Curie grant agreement N° 754397. The ALBA synchrotron is acknowledged for provision of beamtime within the in-house project program (proposals 2019013225 and 2020014004)., Peer reviewed

The combination of the flexible N,N’-ditopic ligand 1,4-bis(4-pyridylmethyl)benzene (bpymb) with zinc(II) acetate (ZnAc) affords the synthesis of the two-dimensional coordination polymer [Zn2Ac2(μ-Ac)2(bpymb)]n, which was structurally characterized by single crystal XRD. In the resolved structure, the molar ratio metal:ligand was 2:1 for Ac:Zn. However, half of the acetate units are acting as bridging ligands, which allows the building of a layered structure. The description of this new structure increases the numerous family of compounds involving zinc acetate and a ditopic N,N’- ligand, and demonstrates a new possible architecture. The obtained coordination polymer was also characterized by elemental analysis, ATR-FTIR spectroscopy and TGA analysis. Besides, the photoluminescence properties of this compound where measured, showing that the weak photoluminescence of the free bpymb ligand increases after polymer formation., This work was financed by the Spanish National Plan of Research with project CTQ2017-83632. C.D. and A.M.L.-P. acknowledge the financial support from the Spanish MEC, through the Severo Ochoa Program for Centres of Excellence in R&D FUNFUTURE (CEX2019-000917-S). ALBA synchrotron is acknowledged for the provision of beam time., Peer reviewed

The author is grateful to ALISTORE-ERI colleagues for helpful discussions and sustained interaction. The Spanish Research Agency is acknowledged for the Severo Ochoa Programme for Centres of Excellence in R&D (CEX2019-000917-S) and AGAUR (Generalitat de Catalunya) for support via grant 2017 SGR 581., Peer reviewed

The high defect tolerance of metal halide perovskites, in terms of their exceptional optoelectronic properties, is assumed to be due to the very fact that most native point defects are shallow, which does not contribute to the non‐radiative recombination of free carriers. Here, a systematic study is presented, which concerns the evolution of shallow‐defect signatures observed at low temperatures in the photoluminescence (PL) spectra of mixed organic‐cation lead iodide perovskite single crystals (FAxMA1−xPbI3, where MA stands for methylammonium and FA for formamidinium). Below ≈100 K, a number of peak‐like features become clearly apparent in the PL spectra at energies lower than the strong free‐exciton emission, which are related to the radiative recombination of bound exciton complexes associated with native shallow defects (donors and/or acceptors). Based on state‐of‐the‐art ab initio calculations, a tentative assignment is provided for all PL features to different shallow‐defects (Pb, I, and MA vacancies as well as I interstitials) typically present in hybrid perovskites. The defect‐related signatures exhibit a clear trend regarding the mixed‐crystal composition, indicating that the material becomes less prone to defect formation with increasing FA content., The authors thank M. Campoy‐Quiles for fruitful discussions. The Spanish “Ministerio de Ciencia e Innovación (MICINN)” is gratefully acknowledged for its support through grant Nos. SEV‐2015‐0496 (FUNMAT) and CEX2019‐000917‐S (FUNFUTURE) in the framework of the Spanish Severo Ochoa Centre of Excellence program and the AEI/FEDER(UE) grant PGC2018‐095411‐B‐100 (RAINBOW). The authors also thank the Catalan agency AGAUR for grant 2017‐SGR‐00488 and the National Network “Red Perovskitas” (MICINN funded). A.F.L. acknowledges an FPI fellowship (BES‐2016‐076913) from MICINN co‐financed by the European Social Fund and the Ph.D. programme in Materials Science from Universitat Autònoma de Barcelona in which he was enrolled. B.C. thanks the EPSRC for Ph.D. studentship funding via the University of Bath, CSCT CDT (EP/G03768X/1)., Peer reviewed

The layered perovskite YBaCuFeO5 (YBCFO) is considered one of the best candidates to high-temperature chiral multiferroics with strong magnetoelectric coupling. In RBaCuFeO5 perovskites (R: rare-earth or Y) A-site cations are fully ordered whereas their magnetic properties strongly depend on the preparation process. They exhibit partial cationic disorder at the B-site that generates a magnetic spiral stabilized through directionally assisted long range coupling between canted locally frustrated spins. Moreover the orientation of its magnetic spiral can be critical for the magnetoelectric response of this chiral magnetic oxide. We have synthesized and studied YBaCuFe1-xMnxO5 samples doped with Mn, with the aim of increasing spin-orbit coupling effects, and found that the overall Fe/Cu cation disorder at the B-sites can be increased by doping without changing the sample preparation process. In YBaCuFe1-xMnxO5 samples prepared under the same conditions, the T-x magnetic phase diagram have been constructed in the range 10 K-500 K combining magnetometry, X-ray and neutron powder diffraction measurements. The tilting angles of the spins in the collinear, θcol, and spiral phases, θspiral, barely vary with temperature. In the collinear phase θcol is also independent of the Mn content. In contrast, the presence of Mn produces a progressive reorientation of the plane of the magnetic helix in the incommensurate phase, capable to transform the helicoidal spin ordering into a cycloidal one, which may critically determine the ferroelectric and magnetoelectric behavior in these compounds. Some of the observations are of interest for engineering and developing this family of potential high-temperature multiferroics., We acknowledge financial support from the Spanish Ministerio de Ciencia, Innovación y Universidades (MINCIU), through Project No. RTI2018-098537-B-C21, cofunded by ERDF from EU, and “Severo Ochoa” Programme for Centres of Excellence in R&D [FUNFUTURE (CEX2019-000917-S)]. X.Z. was financially supported by China Scholarship Council (CSC) with No. 201706080017. X.Z's work was done as a part of the Ph.D program in Materials Science at Universitat Autònoma de Barcelona. We also acknowledge ALBA, ILL and D1B-CRG (MINCIU) for provision of beam time (dois: 10.5291/ILL-DATA.CRG-2655, 10.5291/ILL-DATA.CRG-2478, 10.5291/ILL-DATA.CRG-2562)., Peer reviewed

Fabry disease is a rare lysosomal storage disorder characterized by a deficiency of α-galactosidase A (GLA), a lysosomal hydrolase. The enzyme replacement therapy administering naked GLA shows several drawbacks including poor biodistribution, limited efficacy, and relatively high immunogenicity in Fabry patients. An attractive strategy to overcome these problems is the use of nanocarriers for encapsulating the enzyme. Nanoliposomes functionalized with RGD peptide have already emerged as a good platform to protect and deliver GLA to endothelial cells. However, low colloidal stability and limited enzyme entrapment efficiency could hinder the further pharmaceutical development and the clinical translation of these nanoformulations. Herein, the incorporation of the cationic miristalkonium chloride (MKC) surfactant to RGD nanovesicles is explored, comparing two different nanosystems—quatsomes and hybrid liposomes. In both systems, the positive surface charge introduced by MKC promotes electrostatic interactions between the enzyme and the nanovesicles, improving the loading capacity and colloidal stability. The presence of high MKC content in quatsomes practically abolishes GLA enzymatic activity, while low concentrations of the surfactant in hybrid liposomes stabilize the enzyme without compromising its activity. Moreover, hybrid liposomes show improved efficacy in cell cultures and a good in vitro/in vivo safety profile, ensuring their future preclinical and clinical development., This work was supported by the financial support from European Commission through the H2020 program (Smart-4-Fabry project, ID 720942). The Networking Research Centre on Bioengineering, Biomaterials, and Nanomedicine (CIBER-BBN) is financed by the Instituto de Salud Carlos III (ISCIII) with assistance from the European Regional Development Fund (ERDF). This work was also financed by the Ministerio de Ciencia e Innovación (PID2019-105622RB-I00). The work was also partially funded by ISCIII (PI18_00871 cofounded by ERDF) and CIBER-BBN (EXPLORE) granted to I.A. We also acknowledge the ICTS “NANBIOSIS”, more specifically, the support from the Protein Production Platform of CIBER-BBN/IBB, at the UAB SepBioES scientific-technical service (https://www.nanbiosis.es/portfolio/u1-protein-production-platform-ppp/), the Soft Materials Service linked to Biomaterial Processing and Nanostructuring Unit (U6) at ICMAB-CSIC (www.nanbiosis.es/portfolio/u6-biomaterial-processing-and-nanostructuring-unit/), the Synthesis of Peptide Unit (U3) at the IQAC-CSIC (www.nanbiosis.es/portfolio/u3-synthesis-of-peptides-unit/), and the In Vivo Experimental Platform of the Functional Validation & Preclinical Research (FVPR) area (http://www.nanbiosis.es/portfolio/u20-in-vivo-experimental-platform/). We also thank the denomination of the consolidated group from Generalitat de Catalunya: 2017-SGR-1439 (M.R.) and 2017-SGR-918 (J.V.). J.T.-M. thanks the financial support by the FI-AGAUR grant by the Generalitat de Catalunya, especially the Secretary of Universities and Research of the Department of Business and Knowledge of the Generalitat de Catalunya and the European Social Fund (ESF–Investing in your future) of the European Union. This work has been done in the framework of the J.T.-M. doctorate in Materials Science of the Universitat Autònoma de Barcelona. N.G.-A. is supported by a PERIS grant from the Catalan Government (SLT006/17/270). Authors acknowledge financial support from the Agencia Estatal de Investigación-Ministerio de Ciencia e Innovación through the “Severo Ochoa” Programme for Centres of Excellence in R&D (CEX2019-000917-S)., Peer reviewed

Three radical cation salts of BDH-TTP with the paramagnetic [ReF6]2− and diamagnetic [ReO4]− anions have been synthesized: κ-(BDH-TTP)4ReF6 (1), κ-(BDH-TTP)4ReF6·4.8H2O (2) and pseudo-κ″-(BDH-TTP)3(ReO4)2 (3). The crystal and band structures, as well as the conducting properties of the salts, have been studied. The structures of the three salts are layered and characterized by alternating κ-(1, 2) and κ″-(3) type organic radical cation layers with inorganic anion sheets. Similar to other κ-salts, the conducting layers in the crystals of 1 and 2 are formed by BDH-TTP dimers. The partial population of positions of Re atoms and disorder in the anionic layers of 1–3 are their distinctive features. Compounds 1 and 2 show the metallic character of conductivity down to low temperatures, while 3 is a semiconductor. The ac susceptibility of crystals 1 was investigated in order to test the possible slow relaxation of magnetization associated with the [ReF6]2− anion., This research was funded by the Ministry of Science and Higher Education of the Russian
Federation (Grant No. 075-15-2020-779). Work in Spain was supported by MICIU (through the
Severo Ochoa FUNFUTURE (CEX2019-000917-S) Excellence Centre distinction and Grant PGC
2018-096955-B-C44), and by Generalitat de Catalunya (2017SGR1506)., Peer reviewed

Indium tin oxide (ITO) is the most widely used transparent conductor in applications such as light emitting diodes, liquid crystal devices, touch screens, and photovoltaic cells. So far, its use has mainly been limited to the visible range (380 nm–750 nm), as it reflects at longer wavelengths and, consequently, its transmission is low. Here, we introduce a simple technique, based on high temperature annealing, which can reduce reflection in the near-infrared range (750 nm–2400 nm). With an optimized set of parameters, we were able to modulate the ITO properties and achieve a high transmission, greater than 80% including substrate contribution, at telecommunication wavelengths (C-band, 1530 nm–1565 nm) while still maintaining high electrical conductivity (resistivity <1.9 × 10−4 Ω cm). By using the newly developed infrared ITO transparent conductor, we demonstrate quantum dot solar cells with 27.7% enhancement in external quantum efficiency at the first exciton peak (1650 nm), and liquid crystal switching devices with 25% enhancement in transmission, with respect to device counterparts incorporating commercially available ITO., We acknowledge financial support from the Spanish Ministry of Economy and Competitiveness through Grant No. MAT2017-85232-R (AEI/FEDER, EU) and the Spanish State Research Agency through the “Severo Ochoa” program for Centers of Excellence in R&D (CEX2019-000910-S and CEX2019-000917 S), and project TUNA-SURF (Grant No. PID2019-106892RB-I00), from Fundació Cellex, Fundació Mir-Puig and from Generalitat de Catalunya through the CERCA program through AGAUR Grant Nos. 2017 SGR 1634 and 2017 301 SGR1377. C.G. acknowledges the funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie Grant Agreement No. 713729. This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie Grant Agreement No. 754510. Y.C. acknowledges the China Scholarship Council (Grant No. 201506890029). The authors also acknowledge Vittoria Finazzi for her help and fruitful discussions., Peer reviewed

The molecule 2-decyl-7-phenyl-[1]benzothieno[3,2-b][1]benzothiophene (Ph-BTBT-10) is an organic semiconductor with outstanding performance in thin-film transistors. The asymmetric shape of the molecule causes an unusual phase behavior, which is a result of a distinct difference in the molecular arrangement between the head-to-head stacking of the molecules versus head-to-tail stacking. Thin films are prepared at elevated temperatures by crystallization from melt under controlled cooling rates, thermal-gradient crystallization, and bar coating at elevated temperatures. The films are investigated using X-ray diffraction techniques. Unusual peak-broadening effects are found, which cannot be explained using standard models. The modeling of the diffraction patterns with a statistic variation of the molecules reveal that a specific type of molecular disorder is responsible for the observed peak-broadening phenomena: the known head-to-head stacking within the crystalline phase is disturbed by the statistic integration of reversed (or flipped) molecules. It is found that 7–15% of the molecules are integrated in a reversed way, and these fractions are correlated with cooling rates during the sample preparation procedure. Temperature-dependent in situ experiments reveal that the defects can be healed by approaching the transition from the crystalline state to the smectic E state at a temperature of 145 °C. This work identifies and quantifies a specific crystalline defect type within thin films of an asymmetric rodlike conjugated molecule, which is caused by the crystallization kinetics., This work was supported by the Fonds de la Recherche Scientifique (FNRS) and the Fonds voor Wetenschappelijk Onderzoek – Vlanderen (FWO) under EOS project 30489208 and the Austrian Science Fund (FWF): [P30222]. YG is also thankful to FNRS for financial support through research projects BTBT n° 2.4565.11, Phasetrans n° T.0058.14, Pi-Fast n° T.0072.18, and 2D to 3D No. 30489208. Financial supports from the French Community of Belgian (ARC n° 20061) and by the Walloon Region (WCS No. 1117306, SOLIDYE n° 1510602) are also acknowledged. G.S. acknowledges postdoctoral fellowship support from the FNRS. M.M. thanks the Spanish Ministry project GENESIS PID2019-111682RB-I00, the “Severo Ochoa” Programme for the Centers of Excellence in R&D (FUNFUTURE, CEX2019-000917-S), and the Generalitat de Catalunya (2017-SGR-918). A.T. is enrolled in the Materials Science PhD program of Universitat Autònoma de Barcelona and acknowledges FPU fellowship from the Spanish Ministry. The large-scale facility Elettra, Trieste, Italy, provided synchrotron radiation for grazing incidence X-ray diffraction experiments at the beamline XRD1., Peer reviewed

The control of the spontaneous formation of nanostructures at the surface of thin films is of strong interest in many different fields, from catalysts to microelectronics, because surface and interfacial properties may be substantially enhanced. Here, we analyze the formation of nickel oxide nanocuboids on top of La2Ni1−xMn1+xO6 double perovskite ferromagnetic thin films, epitaxially grown on SrTiO3 (001) substrates by radio-frequency (RF) magnetron sputtering. We show that, by annealing the films at high temperature under high oxygen partial pressure, the spontaneous segregation of nanocuboids is enhanced. The evolution of the structural and magnetic properties of the films is studied as a function of the annealing treatments at different temperatures. It is shown that the formation of NiOx nanocuboids leads to a nanostructured film surface with regions of locally different electrical transport characteristics., We acknowledge financial support from the Spanish Ministry of Science, Innovation
and Universities through Severo Ochoa Program (CEX2019-000917-S) and RTI2018-099960-B-I00
(SPINCURIOX) and funding from the European Union’s Horizon 2020 research and innovation
program under the Marie-Sklodowska-Curie grant agreement No. 645658 (DAFNEOX Project) and
FEDER Program. Z.K. acknowledge the support of the Serbian Ministry of Education, Science and
Technological Development (III45018). This work has been performed in the framework of the PhD
program of the Universitat Autonoma de Barcelona (UAB)., Peer reviewed