Universal Existence of Localized Single‐Photon Emitters in the Perovskite Film of All‐Inorganic CsPbBr<sub>3</sub> Microcrystals
Shengnan Feng, Qilin Qin, Xiaopeng Han, Chunfeng Zhang, Xiaoyong Wang, Tao Yu, Min Xiao
Abstract
Abstract All‐inorganic halide perovskites have drawn a lot of research attention very recently owing to their potential solution to the instability issue currently faced by the organic–inorganic counterparts. Meanwhile, the halide perovskites in a solid film are manifested as microscale morphologies whose functionalities are unavoidably affected by the interior or exterior presence of various nanoscale entities. Here all‐inorganic solid films are fabricated with varying densities of single CsPbBr 3 microcrystals, showing that very sharp photoluminescence peaks can be universally observed at 4 K with the linewidths being as narrow as hundreds of μeV. The single‐photon emission nature is confirmed for such a photoluminescence peak, whose intensity is completely quenched above ≈30 K to suggest its possible origin from a low potential‐energy region of the single microcrystal. The discovery of such a novel emitting species in halide perovskites, with the enriched structure–property relationship, will surely impart significant influences on the advancement of relevant optoelectronic devices and quantum‐light sources.