Abstract

The AMX3 (A = Cs, Rb, CH3NH3 ; M = Pb, Sn, Ge; X = I, Br, Cl) halide perovskites are an amazing class of materials. Their electrical and optical properties are comparable to conventional compound semiconductors, which makes them potentially suitable for many applications, including solar cells where power conversion efficiencies exceeding 20% have been realized. Unlike conventional semiconductors halide perovskites can be prepared from solution, which opens up an entirely new realm of processing conditions. In addition, the electronic structure and optoelectronic properties of halide perovskites can be tuned through distortions of the crystal structure. In this talk I will discuss our work on Cs1−xRbxPbBr3 and Cs1−xRbxPbCl3 solid solutions, as well as our efforts to synthesize and characterize new halide double perovskites with compositions Cs2BB′X6 (B = Ag, Na; B′ = Bi, Sb, In; X = Cl, Br). Drawing from our work, as well as others, I will offer an experimentalists perspective on the forces stabilize the perovskite structure among halides, and the effect of structural distortions on the electronic structure and optical properties of these materials.