Epitaxial Electrodeposition of Methylammonium Lead Iodide Perovskites

An electrochemical/chemical route is introduced to deposit both textured and epitaxial films of methylammonium lead iodide (MAPbI₃) perovskites. The perovskite films are produced by chemical conversion of lead dioxide films that have been electrodeposited as either textured or epitaxial films onto [111]-textured Au and [100] and [111] single-crystal Au substrates. The epitaxial relationships for the MAPbI₃ films are MAPbI₃(001)­[010]∥PbO₂(100)⟨001⟩ and MAPbI₃(110)­[111]∥PbO₂(100)⟨001⟩ regardless of the Au substrate orientation, because the in-plane order of the converted film is controlled by the epitaxial PbO₂ precursor film. The textured and epitaxial MAPbI₃ films both have trap densities lower than and photoluminescence intensities higher than those of polycrystalline films produced by spin coating

On spectral radii of matrices governing some numerical estimating algorithms with incomplete data

Convergence, Convergence rates, Incomplete data, Inference with missing observations, Em and EM-bayes algorithms, Functional approximations, Matrix spectral radii and leading eigenvalue, 62A10, 62E20, 62F10, 62F30,