Charge-Carrier Dynamics and Mobilities in Formamidinium Lead Mixed-Halide Perovskites

Abstract

The mixed-halide perovskite FAPb(BryI1-y)3 is attractive for color-tunable and tandem solar cells. Bimolecular and Auger charge-carrier recombination rate constants strongly correlate with the Br content, y, suggesting a link with electronic structure. FAPbBr3 and FAPbI3 exhibit charge-carrier mobilities of 14 and 27 cm2 V-1 s-1 and diffusion lengths exceeding 1 μm, while mobilities across the mixed Br/I system depend on crystalline phase disorder.