3D hybrid perovskite solid solutions: a facile approach for deposition of nanoparticles and thin films via B-site substitution

Abstract

Mixed metal halide perovskites are gaining paramount interest due to efficient band gap tenability and improved optical properties compared to their single metal halide perovskites. It is thus valuable to investigate compositional changes in lead halide perovskites to explore energy changes. Herein, we report the synthesis of a lead to lead free hybrid perovskite solid solution (CH₃NH₃Pb_1−xCu_xBr₃) as nanoparticles and films. The increasing concentration of Cu²⁺ ions in the site of the Pb²⁺ ion in the perovskite shifted the diffraction peaks to a larger angle. Uniform spherically shaped nanoparticles were synthesized by a wet chemical method, the higher Cu²⁺ concentration leads to agglomeration, producing sheet like morphologies. However, the deposition of thin films of CH₃NH₃Pb_1−xCu_xBr₃ perovskite solid solution shows that well defined morphologies begin to appear with increasing concentrations of Cu²⁺ in the perovskite structure. The as-prepared bulk lead free CH₃NH₃CuBr₃ perovskite shows a band gap of 1.65 eV. A blue shift in photoluminescence (PL) was observed with copper enriched hybrid perovskites.