Ultrafast carrier dynamics in all-inorganic CsPbBr₃ perovskite across the pressure-induced phase transition

Abstract

The excited-state carrier dynamics of lead halide perovskites play a critical role in their photoelectric properties, and are greatly affected by lattice structural changes. In this work, the carrier dynamics of all-inorganic CsPbBr₃ peroveskite, as a function of pressure, are investigated using in situ high-pressure femtosecond transient absorption spectroscopic experiments. Compression is found to drive crystal structural evolution, thereby markedly changing the behavior of charge carriers in CsPbBr₃. Before the phase transition, simultaneous prolonging of the carrier relaxation and Auger recombination is achieved alongside a narrowing in the bandgap. The results favor improved efficiency and photovoltaic performance.