Exploring the phase diagram of FAPbI3 using in situ reflectance spectroscopy

Tobias Siegert, Lorenz Kiel, Prerna Pahwa, Christina Witt, Konstantin Schötz, Frank-Julian Kahle, Markus Griesbach, Fabian Panzer, Harald Oberhofer, Ralf Moos, Helen Grüninger and Anna Köhler

α Phase formamidinium lead iodide (FAPbI3) is a promising perovskite absorber for high-efficiency photovoltaics, yet it is metastable under ambient conditions and converts to the unsuitable hexagonal δ phase. We investigate the combined influence of temperature and pressure on the phase behavior of FAPbI3 using a home-built hot-press system coupled with an in situ optical […]

[DOI]