Giant Superbunching Emission from Mesoscopic Perovskite Emitter Clusters

Abstract Photon superbunching, as a crucial resource for photonic quantum technologies, is investigated in several systems. This phenomenon can be induced by both coherent collective spontaneous processes such as superfluorescence and superradiance, and cascaded emission. Although superbunching emission induced by superfluorescence and cascaded emission is demonstrated recently in perovskite quantum dot (QD) superlattice and single perovskite QD, the effect itself is not that strong, especially in the former case with a second‐order photon correlation g (2) (0) only slightly larger than 2. Here, the superbunching emission from mesoscopic CsPbBr 3 emitter clusters is reported. The higher temperature and excitation power are found to suppress the superbunching effect significantly. Compared with the former results in the literature, under the same experimental conditions, that is, temperature and excitation power, much larger g (2) (0) with the maximum value of 21 being achieved at 1.6 K with an excitation power of 0.1 µW is observed. The discoveries here improve the understanding of superbunching emission in perovskite‐based materials and will enable their application in developing multi‐photon light sources for photonic quantum technologies.