Charge-carrier dynamics in vapour-deposited films of the organolead halide perovskite CH3NH3PbI3−xClx

Abstract

We determine high charge-carrier mobilities ≥ 33 cm² V⁻¹ s⁻¹ and bi-molecular recombination rates about five orders of magnitude below the prediction of Langevin's model for vapour-deposited CH₃NH₃PbI_3−xCl_x using ultrafast THz spectroscopy. At charge-carrier densities below ∼10¹⁷ cm⁻³ intrinsic diffusion lengths are shown to approach 3 microns, limited by slow mono-molecular decay processes.