Tunable vacancy ordering for defect tolerant hybrid halide semiconductors

Abstract

Hybrid halide perovskites have proven to be promising semiconductor materials for applications in photovoltaics, neuromorphic computing, energy storage, and light-emitting diodes. Compared with conventional, well-studied semiconductors (e.g. Si, GaAs, CdTe), hybrid halide perovskites are uniquely defect-tolerant and maintain their optoelectronic properties despite having intrinsic high equilibrium defect concentrations. Tin-based hybrid halide perovskites are a less toxic and underexplored alternative to Pb-based counterparts, but suffer from intrinsic oxidation, uncontrolled doping, and structural disorder that limits their optoelectronic properties and applications. Here, we explore the crystal structures and resulting properties of Sn-based hybrid halide perovskites materials that exhibit vacancy-ordered defects while maintaining ideal 3D structural connectivity. By synthesizing multiple seven carbon diammonium organic A-site cations with Sn (II), Sb (III), and Bi (III) and characterizing the distinct optoelectronic properties of each, we aim to establish the underlying enthalpic and entropic mechanisms that permit defect tolerance and dopability in hybrid halide perovskites for use in next-generation semiconducting materials.