Inhibiting the Auger recombination of perovskite micro-rod laser through the monolayer graphene

In past few years, while lead halide perovskite micro-lasers have been thoroughly studied, their performances at high excitation power have rarely explored. Here, we study the perovskite micro-lasers with high pumping density and explore the mechanism to improve their laser characteristics. By transferring a CH
3
NH
3
PbBr
3
perovskite micro-rod onto a few-layered graphene slice, whispering gallery like lasing modes have been formed in the transverse plane of the microrod. Interestingly, the “gain saturation” of conventional CH
3
NH
3
PbBr
3
perovskite micro-rod laser has been released. The maximal output intensity has been significantly improved more than 4 times and the threshold is reduced around 20%. The following experiments show that such improvements are caused by the electron acceptor property of graphene. By attracting electron with graphene, the electrons and holes are partially separated in the hybrid perovskite/graphene system and thus the Auger recombination at high pumping power has been inhibited. We believe that our finding will be important not only for the perovskite lasers but also for other semiconductor light emitting devices.