Room-temperature synthesis of excellent-performance CsPb1-xSnxBr3 perovskite quantum dots and application in light emitting diodes

Abstract

The traditional hot injection (HI) process needs high temperature, inert gas protection, and localized injection operation, which severely hinder their large-scale industrialization. Moreover, the CsPb1-xSnxBr3 HI-QDs exhibit poor stability. Herein, we report the room-temperature (RT) synthesis of CsPb1-xSnxBr3 perovskite QDs by modified ligand-assisted reprecipitation (LARP) approach. Compared with the CsPb1-xSnxBr3 HI-QDs reported in literatures, the CsPb1-xSnxBr3 RT-QDs show higher photoluminescence quantum yield (PLQY) and better stability: the CsPb0.9Sn0.1Br3 RT-QDs obtain the highest PLQY of more than 91%, and the stability of the film made with this QDs still maintain more than 80% of its original fluorescence strength after 120 days in air environment. Because of the superior PLQY, light-emitting diodes (LEDs) based on the RT-QDs is constructed, and it exhibits an external quantum efficiency (EQE) of 1.8%, a luminance of 1600 cdm-2, a current efficiency of 4.89 cdA-1, a power efficiency of 6.41 lmw−1, and a low on-voltage of 3.6 V. The present work provides a feasible method for large-scale industrial synthesis of perovskite QDs at room temperature and shows that the CsPb1-xSnxBr3 RT-QDs are promising for highly efficient LEDs. Keywords: Room-temperature synthesis, CsPb1-xSnxBr3 perovskite quantum dots, High quantum yield, Outstanding stability, Light-emitting diodes