Mechanochemical synthesis of 0D and 3D cesium lead mixed halide perovskites

Abstract

A simplified mechanochemical synthesis approach for Cs-containing mixed halide perovskite materials of lower and higher dimensionality (0D and 3D, respectively) is presented with stoichiometric control from their halide salts, CsX and PbX₂ (X = Cl, Br, I). Excellent optical bandgap tunability through halide substitution is supported by property measurements and changes to the materials' structure. Complementary NMR and XRD methods, along with support from DFT calculations, reveal highly crystalline 0D and 3D solid solutions with a complex arrangement of [PbX_6−xX_x′]⁴⁻ pseudooctahedra caused by halide distribution about the Pb centre.