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Perovskite have had a great impact on the solid-state physics world in the last decade not only achieving great success in photovoltaics but, more recently, also in the implementation of other optoelectronic devices. One of the main obstacles for the adoption of Pb-based perovskite technologies are the high amounts of Pb needed in the conventional preparation methods. Here we present for the first time a detailed analysis of the photophysical and photoelectrochemical properties of CsPbBr

Sodium based titanate nanostructures (NaTNT) are promising materials for energy storage and photoelectrode applications. We present an experimental work describing the structural, morphological and electronic properties of hydrothermally synthesized NaTNT, evaluating different synthesis conditions (synthesis temperature and time). We found a clear dependence between the synthesis condition and the observed, morphological, electrical and optical features. Increasing synthesis time and decreasing temperature allow the nanotubes to be filled. Local and extended structural analysis, and Raman spectroscopy, supported the samples stoichiometry with a pentacoordinated Ti-O polyhedral. Electrochemical impedance spectroscopy analysis revealed a predominant two-transport mechanism; however, a third process was observed for two samples with particular morphology (nanorods and nanoparticles co-existing with nanotubes). Finally, the influence on the optical properties of the structural and morphological characteristic is determined and discussed. We found a reduction of the gap energies when compared with anatase. Additionally, from the photoluminescence response we suggest different kind of defects must be present in the samples. This work presents a very complete set of experimental tools for the analysis of NaTNT, showing how the synthesis conditions allow tuning the electrical and optical responses of NaTNT for energy storage and photoelectrode applications.

As-grown and chloride-doped ZnO nanopillars were electrodeposited onto bareFTO/glass and ZnO-compact layer/FTO/glass substrates. To analyse the effect of the presence of chloride ions in the electrolytic bath, NH4Cl was progressively added up to 0.02 mol L-1. As preliminary examination, the morphology of ZnO nanostructures was analysed by SEM micrographs and chlorine incorporation was detected by EDS. Then, a detailed analysis comprising structural, electrical, optical and defect properties was constructed using XRD, electrical resistance measurements and UV-Vis-IR spectroscopy. As the chlorine concentration in the film increases, XRD reveals a displacement of diffracted planes due to macrostrain of the ZnO lattice and the electrical resistance diminishes. Also, the UV optical absorption edge shifts to higher energies due to Moss-Burstein effect which corresponds to electron densities in the order of 1 to 6 x 1019 cm-3, and the infrared spectra reveal the presence of free electrons, allowing a moreprecise determination of the free electron densities. Fil: Berruet, Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentina Fil: Gau, D. L. Universidad de la Republica. Facultad de Ingeniería. Departamento de Física; Uruguay Fil: Dalchiele, E.A. Universidad de la Republica. Facultad de Ingeniería. Departamento de Física; Uruguay Fil: Vazquez, Marcela Vivian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentina Fil: Marotti, R.E. Universidad de la Republica. Facultad de Ingeniería. Departamento de Física; Uruguay

The solar absorptance αs of nanostructured selective surface (NSS) for solar thermal energy is improved. The NSS are prepared by AC electrochemical impregnation of metal inclusions (MI) into porous anodized aluminum oxide (AAO). The dependence of the NSS performance with composition depth profile and MI is studied by numeric simulations based in a gradient index model and effective medium theory. The results are compared with experimental NSS prepared varying three control parameters and MI (Ni, Cu, Ag). The αs is improved to > 85% (keeping thermal emittance εT relatively low) for Ni MI, mainly by increasing MI content. Increasing AAO thickness or MI molecular weight (for a given experimental composition profile) also improves the performance. For Ag the αs was further improved to 90%.