Formamidinium Lead Bromide (FAPbBr3) Perovskite Microcrystals for Sensitive and Fast Photodetectors

摘要

Because of the good thermal stability and superior carrier transport characteristics of formamidinium lead trihalide perovskite HC(NH2)2PbX3 (FAPbX3), it has been considered to be a better optoelectronic material than conventional CH3NH3PbX3 (MAPbX3). Herein, we fabricated a FAPbBr3 microcrystal-based photodetector that exhibited a good responsivity of 4000 A W⁻¹ and external quantum efficiency up to 10⁶% under one-photon excitation, corresponding to the detectivity greater than 10¹⁴ Jones. The responsivity is two orders of magnitude higher than that of previously reported formamidinium perovskite photodetectors. Furthermore, the FAPbBr3 photodetector’s responsivity to two-photon absorption with an 800-nm excitation source can reach 0.07 A W⁻¹, which is four orders of magnitude higher than that of its MAPbBr3 counterparts. The response time of this photodetector is less than 1 ms. This study provides solid evidence that FAPbBr3 can be an excellent candidate for highly sensitive and fast photodetectors.Electronic supplementary materialThe online version of this article (10.1007/s40820-018-0196-2) contains supplementary material, which is available to authorized users.