title: Low surface recombination velocity in solution-grown CH3NH3PbBr3 perovskite single crystal.
abstract: Organic-inorganic hybrid perovskites are attracting intense research effort due to their impressive performance in solar cells. While the carrier transport parameters such as mobility and bulk carrier lifetime shows sufficient characteristics, the surface recombination, which can have major impact on the solar cell performance, has not been studied. Here we measure surface recombination dynamics in CH3NH3PbBr3 perovskite single crystals using broadband transient reflectance spectroscopy. The surface recombination velocity is found to be 3.4±0.1 × 10(3) cm s(-1), ∼2-3 orders of magnitude lower than that in many important unpassivated semiconductors employed in solar cells. Our result suggests that the planar grain size for the perovskite thin films should be larger than ∼30 μm to avoid the influence of surface recombination on the effective carrier lifetime.
authors.affiliation: National Renewable Energy Laboratory (NREL), Golden, Colorado 80401, USA.
authors.forename: Ye
authors.initials: Y
authors.lastname: Yang
authors.affiliation: National Renewable Energy Laboratory (NREL), Golden, Colorado 80401, USA.
authors.forename: Yong
authors.initials: Y
authors.lastname: Yan
authors.affiliation: National Renewable Energy Laboratory (NREL), Golden, Colorado 80401, USA.
authors.forename: Mengjin
authors.initials: M
authors.lastname: Yang
authors.affiliation: National Renewable Energy Laboratory (NREL), Golden, Colorado 80401, USA.
authors.forename: Sukgeun
authors.initials: S
authors.lastname: Choi
authors.affiliation: National Renewable Energy Laboratory (NREL), Golden, Colorado 80401, USA.
authors.forename: Kai
authors.initials: K
authors.lastname: Zhu
authors.affiliation: National Renewable Energy Laboratory (NREL), Golden, Colorado 80401, USA.
authors.forename: Joseph M
authors.initials: JM
authors.lastname: Luther
authors.affiliation: National Renewable Energy Laboratory (NREL), Golden, Colorado 80401, USA.
authors.forename: Matthew C
authors.initials: MC
authors.lastname: Beard