Short Photoluminescence Lifetimes in Vacuum-Deposited CH<sub>3</sub>NH<sub>3</sub>PbI<sub>3</sub> Perovskite Thin Films as a Result of Fast Diffusion of Photogenerated Charge Carriers ChirvonyVladimir S. SekerbayevKairolla S. Pérez-del-ReyDaniel Martínez-PastorJuan P. PalazonFrancisco BoixPablo P. TaurbayevToktar I. SessoloMichele BolinkHenk J. 2019 It is widely accepted that a long photoluminescence (PL) lifetime in metal halide perovskite films is a crucial and favorable factor, as it ensures a large charge diffusion length leading to a high power conversion efficiency (PCE) in solar cells. It has been recently found that vacuum-evaporated CH<sub>3</sub>NH<sub>3</sub>PbI<sub>3</sub> (eMAPI) films show very short PL lifetimes of several nanoseconds. The corresponding solar cells, however, have high photovoltage (>1.1 V) and PCEs (up to 20%). We rationalize this apparent contradiction and show that eMAPI films are characterized by a very high diffusion coefficient <i>D</i>, estimated from modeling the PL kinetics to exceed 1 cm<sup>2</sup>/s. Such high <i>D</i> values are favorable for long diffusion length as well as fast transport of carriers to film surfaces, where they recombine nonradiatively with surface recombination velocity <i>S</i> ∼ 10<sup>4</sup> cm/s. Possible physical origins leading to the high <i>D</i> values are also discussed.