Cesium lead halide perovskite materials have attracted considerable attention for potential applications in lasers, light emitting diodes and photodetectors. Here, we provide the experimental and theoretical evidence for photon recycling in CsPbBr3 perovskite microwires. Using two-photon excitation, we recorded photoluminescence (PL) lifetimes and emission spectra as a function of the lateral distance between PL excitation and collection positions along the microwire, with separations exceeding 100 µm. At longer separations, the PL spectrum develops a red-shifted emission peak accompanied by an appearance of well-resolved rise times in the PL kinetics. We developed quantitative modeling that accounts for bimolecular recombination and photon recycling within the microwire waveguide and is sufficient to account for the observed decay modifications. It relies on a high radiative efficiency in CsPbBr3 perovskite microwires and provides crucial information about the potential impact of photon recycling and waveguide trapping on optoelectronic properties of cesium lead halide perovskite materials.
KAUST Repository Item: Exported on 2020-10-01
Acknowledgements: KAUST group (ID, MDB, BT, LS, AAZ, OFM and OMB) gratefully acknowledge funding support from KAUST, Technology Innovation Center for Solid-State Lighting at KAUST. The work of UT Dallas group (YZ, TG, YNG and AVM) was supported by the U.S. Department of Energy, Office of Basic Energy Sciences, Division of Materials Sciences and Engineering under Award No. DE-SC0010697. AVM gratefully acknowledges travel support from CRDF Global at early stages of the work. MIS acknowledges the Government of Canada’s Banting Postdoctoral Fellowship Program for financial support.