Abstract:
In the past decade, lead halide perovskites have dramatically transformed photovoltaic research. Single-junction perovskite solar cells have now been made with efficiencies exceeding those of crystalline silicon, while silicon-perovskite tandems promise to greatly reduce the manufacturing costs associated with high-performance multi-junction devices. Yet despite these excellent efficiencies, lead halide perovskites can be prone to degradation when exposed to heat, light, and moisture, limiting their commercial viability. In this talk, I will discuss our research group’s efforts to elucidate device failure mechanisms in perovskite solar cells. Our work uses both in situ and fully operando X-ray scattering measurements at the Canadian Light Source to show how changes in the composition and crystallinity of the perovskite layer affect device performance. Our results show how relative humidity, temperature, and electrical bias all serve to facilitate ionic motion within the perovskite layer and the important implications that this has for device longevity.