Lack of Photon Antibunching Supports Supertrap Model of Photoluminescence Blinking in Perovskite Sub-Micrometer Crystals

Antibunching effect is typically observed in individual systems possessing photoluminescence (PL) blinking and vice versa. Contrary to this common perception, absence of antibunching in strongly blinking methyl ammonium led tri-iodide (MAPbI₃) perovskite crystals of sizes from tens to hundreds of nanometers regardless of the excitation power density is observed. Antibunching effect does not appear even when photon statistics are analyzed for bright and intermediate PL intensity levels independently. This shows that there is no directional energy funneling and accumulation of charge carriers in the small local regions in MAPbI₃ crystals where an Auger recombination can potentially suppress the simultaneous emission of two photons. This result allows for the exclusion of the PL blinking mechanism based on the idea of emitting sites previously hypothesized for perovskites. Therefore, the model of PL blinking in perovskite crystals based on the presence of a metastable non-radiative recombination center (the supertrap) is the only one proposed so far which explains blinking without conflicting with the absence of photon correlations.