Blinking Mechanisms and Intrinsic Quantum-Confined Stark Effect in Single Methylammonium Lead Bromide Perovskite Quantum Dots

Small. 2020 Dec;16(51):e2005435. doi: 10.1002/smll.202005435. Epub 2020 Nov 25.

Abstract

Lead halide perovskite quantum dots (QDs) are promising materials for next-generation photoelectric devices because of their low preparation costs and excellent optoelectronic properties. In this study, the blinking mechanisms and the intrinsic quantum-confined Stark effect (IQCSE) in single organic-inorganic hybrid CH3 NH3 PbBr3 perovskite QDs using single-dot photoluminescence (PL) spectroscopy is investigated. The PL quantum yield-recombination rates distribution map allows the identification of different PL blinking mechanisms and their respective contributions to the PL emission behavior. A strong correlation between the excitation power and the blinking mechanisms is reported. Most single QDs exhibit band-edge carrier blinking under a low excitation photon fluence. While under a high excitation photon fluence, different proportions of Auger-blinking emerge in their PL intensity trajectories. In particular, significant IQCSEs in the QDs that exhibit more pronounced Auger-blinking are observed. Based on these findings, an Auger-induced IQCSE model to explain the observed IQCSE phenomena is observed.

Keywords: blinking mechanisms; intrinsic quantum-confined Stark effect; perovskite quantum dots; photoluminescence blinking.