Morphology evolution towards ultra-stable mixed tin-lead perovskite via compositional engineering

Abstract

Layered perovskites can be a substitute for bulk perovskites that can solve the stability issues in devices. In this work, we demonstrate the synthesis of ultra-stable and highly luminescent mixed tin-lead quasi two-dimensional (2D) and nanowire perovskite structures by compositional engineering. Ligand assisted reprecipitation method under ambient conditions leads to the formation of low dimensional perovskite nanostructures. By varying lead to the tin ratio in the precursor solution, the dimensions of perovskites vary from three dimensional (3D) to quasi 2D and one-dimensional (1D). Multiple phases (a mixture of 2D quasi 2D and 1D) having different energy bandgaps lead to charge concentration at the excited state of phase having the lowest bandgap (3D) and subsequent funneling type of emission, hence result in high photoluminescence quantum yield.