Proceedings of International Conference on Hybrid and Organic Photovoltaics (HOPV19)
DOI: https://doi.org/10.29363/nanoge.hopv.2020.087
Publication date: 6th February 2020
Various charge carrier mobility under different carrier densities regime have been reported for lead halide perovskite polycrystalline films.[1-3] However, ambiguities in the evaluation of these properties remain, especially time-dependent change of internal carrier population due to early-time recombination should be reflected in long-range lateral charge transport through intragrains and grain boundaries.[1] Here we demonstrate a new transient photo-conductivity technique and accurately estimate the internal free carrier density using simulation of charge population rise and decay with the early-time recombination.[1-4] With this knowledge we determine carrier density invariable lateral mobilities to be in the range from 8.9 down to 0.2 cm2/Vs for Cs0.17FA0.83Pb(I0.9Br0.1)3, Cs0.05(FA0.83MA0.17)0.95Pb(I0.9Br0.1)3 and CH3NH3PbI3 polycrystalline perovskite films depending upon the preparation route and free carrier density. Our results provide the first accurate evaluation of the carrier density invariable lateral mobility in lead halide perovskite films, presenting the applicability of our technique to a broader set of materials and techniques in the research community.
This project was funded by EPSRC, Engineering and Physical Sciences Research Council grants, EP/M005143/1.