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

The mixed-halide perovskite FAPb(Br(gamma)l(1-gamma))(3) is attractive for color-tunable and tandem solar cells. Bimolecular and Auger charge-carrier recombination rate constants strongly correlate with the Br content, gamma, suggesting a link with electronic structure. FAPbBr(3) and FAPbI(3) exhibit charge-carrier mobilities of 14 and 27 cm(2) V-1 s(-1) and diffusion lengths exceeding 1 pm, while mobilities across the mixed Br/l system depend on crystalline phase disorder.