Local structure analysis of Al-containing magnesium silicate perovskite has been carried out with X-ray absorption spectra recorded at the Mg, Al, and Si K-edges using the SA32 beam-line of SuperAco (Orsay, France). The Al-XAFS spectrum of (MgSi)0.85Al0.3O3 perovskite (synthesized in a multi-anvil apparatus) cannot be explained by assuming that Al31 occurs in octahedral or dodecahedral sites on...

Pb2MReO6 (M = Co, Cr) perovskites were prepared by high pressure−high temperature method. Rietveld refinements of synchrotron powder X-ray diffraction show that the crystal structure of Pb2CoReO6 is trigonal (space group R-3) with almost complete ordering of Co and Re cations, while Pb2CrReO6 (space group Pm-3m) is a cubic perovskite with one single site for Cr and Re atoms. The difference betw...

Organometal-halide perovskite solar cells have greatly improved in just a few years to a power conversion efficiency exceeding 20%. This technology shows unprecedented promise for terawatt-scale deployment of solar energy because of its low-cost, solution-based processing and earth-abundant materials. We have studied charge separation and transport in perovskite solar cells-which are the fundam...

Organic–inorganic hybrid perovskite solar cells (PSCs) have emerged as a new class of optoelectronic semiconductors that revolutionized the photovoltaic research in the recent years. The perovskite solar cells present numerous advantages include unique electronic structure, bandgap tunability, superior charge transport properties, facile processing, and low cost. Perovskite solar cells have dem...

[1] The electronic spin and valence states of Fe in post‐ perovskite ((Mg0.75Fe0.25)SiO3) have been investigated by synchrotron X‐ray diffraction, Mössbauer and X‐ray emission spectroscopy at 142 GPa and 300 K. Rietveld refinement of the X‐ray diffraction patterns revealed that our sample was dominated by CaIrO3‐type post‐perovskite. Combined Mössbauer and X‐ray emission results show that Fe in...

We present investigations on the interface formation between the hybrid perovskite MAPbI3 and various substrates, covering a wide range of work functions. The perovskite films are incrementally evaporated in situ while the electronic structure is evaluated using photoelectron spectroscopy. Our results show that there is an induction period in the growth of the perovskite during which volatile c...

In this work, we examine the transferability of a pairwise potential model (derived for MgSiO3 perovskite) to accurately compute the excess energies of the generalized stacking faults (GSF, also called γ-surfaces) in MgSiO3 post-perovskite. All calculations have been performed at 120 GPa, a pressure relevant to the D″ layer. Taking into account an important aspect of crystal chemistry for compl...

Hybrid organic-inorganic perovskite has proved to be a superior material for photovoltaic solar cells. In this work we investigate the parameters influencing the growth of ZnO nanowires (NWs) for use as an efficient low temperature photoanode in perovskite-based solar cells. The structure of the solar cell is FTO (SnO₂:F)-glass (or PET-ITO (In₂O₃·(SnO₂) (ITO)) on, polyethylene terephthalate (PE...

Lead zirconate titanate (PZT) nanopowders with spherical-shaped morphology, perovskite structure and an average size of 20 nm were successfully synthesized. The prepared PZT nanopowders were characterized by differential thermal analysis (DTA), X-ray diffraction (XRD), scanning electron microscopy (SEM), Energy dispersive X-ray (EDS) and Transmission electron microscopy (TEM) technique. Single-...

The atomic structure of a planar defect with a ~001! habit plane in single crystal layered perovskite SrBi2Ta2O9 is determined by high-resolution Z-contrast imaging. We found that the defect forms a structure, with two Sr–Ta–O perovskite blocks connected by a metallic Sr2 plane, rather than a Bi2O2 layer as in the perfect crystal. This defect is expected to be an efficient hole trap and may hav...