(358a) Complementary Molecular and Nanoscale Approaches to Understanding and Improving Metal Halide Perovskite Stability

Metal halide perovskites are promising materials for next-generation optoelectronic applications, but chemical and mechanical instabilities remain barriers to commercial viability. I will discuss the efforts in my research group to address these instabilities through multiple complementary pathways. One approach of interest to address chemical instabilities is incorporating organic additives into the metal halide perovskites that can passivate undercoordinated surface sites. While there has been a large body of literature focused on defect passivation by additives, few design rules have been developed to date. We are attempting to better understand the interactions of passivating organic additives with metal halide perovskites and the influence of molecular structure and function in a generalizable approach. Conversely, the extreme intrinsic fragility of perovskites is a challenge that must be addressed through other means. I will discuss the use of extrinsic approaches to improving the stability of perovskite thin films. In particular, I will highlight the strategy of nanocompositing with polymeric nanofibers developed by my group, which can increase the fracture energy by at least 5-fold without a reduction in device performance. Although there is currently no “one-size-fits-all” approach to fully address the instabilities in metal halide perovskites, complementary strategies can be developed to overcome these challenges.