Polarized Photoluminescence from Lead Halide Perovskites

Abstract Solution‐processable lead halide perovskites possess excellent optical and electronic properties as one of the best candidates for optoelectronics. Especially, some of the perovskites show high quantum efficiency in photoluminescence, which enables their promising application in next‐generation light‐emitting materials and devices. More interestingly, the highly crystalline nature of perovskites as well as the intrinsic spin selectivity of exciton transitions introduces fascinating polarization properties into the light emission from lead halide perovskites. Herein are summarized the recent advances in the studies of polarized photoluminescence from lead halide perovskites in terms of both in‐depth understanding and potential application. The bright excitons in perovskite materials provide spin sublevels that give rise to radiative transitions carrying angular momentum, which is essential for the observation of polarized light emission. The polarization in photoluminescence can be amplified or modulated by introducing functional units such as chiral ligands in the chemical components of perovskites. Incorporating highly ordered microstructures into the perovskite materials is proved to be an effective way to further enhance the polarization properties at the macroscopic scale. The chemical and structural versatility of lead halide perovskites allows utililization of their characteristics of optical polarization in the construction of light sources, photodetectors, display devices, and so on.