Peering into Perovskite Halides with in situ Microscopy: Identifying Routes to Improve Operational Stability

The compositional and process flexibility of halide perovskites is fundamentally attractive for discovering new materials and novel functionality. However, the relatively flat energy landscape of organic-inorganic halide perovskites also gives rise to challenges due to impurity formation during synthesis, process sensitivity, and performance degradation over time. In this talk, I will focus on our efforts to understand and reign in the substantial microscopic complexities in halide perovskites for solar energy conversion and the design of perovskite synthesis and interface chemistry for stability. I will highlight in situ electron and especially X-ray microscopy as powerful lenses to investigate the relationship between nanoscale chemistry, synthesis process, and functional properties for perovskite photovoltaic materials. By assembling correlative microscopy data at the nanoscale in unadulterated film and device stacks, the in situ microscopy provides foundational insights regarding crystallization pathways to reduce structural defects and improve optoelectronic operational stability.