Perspective on Understanding the Origin of Trapped Exciton in Lead‐Halide Perovskite with Broadband Emission

Abstract It has been widely observed that the lead‐halide perovskites can exhibit a highly efficient broadband emission of trapped exciton (TE), and therefore are regarded as promising candidates for the fabrication of next‐generation high‐performance white light sources. However, an unequivocal understanding of the origin of TE is still lacking, and under some circumstances whether the TE is assigned to self‐trapped or defect‐trapped state remains controversial. In this Perspective article, the focus is on the current issues and challenges in theoretical prediction and experimental validation of the transient‐state configuration of TE formed in lead‐halide perovskites. Possible future research directions, including establishing more rigorous theoretical models and developing innovative experimental methods, are also put forward, with the aim of advancing the development and application of these broadband‐emitting perovskite materials in emerging optoelectronic technologies.