Effect of phase distribution and defect passivation on amplified spontaneous emission of quasi-2D Dion–Jacobson perovskite

Abstract

Quasi-2D Dion–Jacobson (DJ) halide perovskites with large exciton binding energy, self-assembled quantum wells, and high quantum yield attract growing attention in light-emitting diodes and solar devices. DJ-layered perovskites have the eliminated van der Waals gap and show improved photophysical features. However, there are a variety of defects and complex phase distributions produced during the solution procedure and the fast crystal development. In this paper, we reveal the effect of phase distribution and defect passivation on amplified spontaneous emission of quasi-2D perovskite (PDMA)(MA)2Pb3Br10 thin films through solvent engineering and additive methods, by establishing the correlation between the precursor compositions and the photophysical performance of the layered DJ perovskites. The energy transfer rate and the photoluminescence quantum yield increase due to the spatially homogeneous domain distribution and the reduced defect density after the addition of KBr in the DMSO:DMF. More importantly, we realize green amplified spontaneous emission and single-mode vertical-cavity surface-emitting lasing with low thresholds of 8.8 and 10.5 μJ cm−2, respectively. This work provides a guideline to achieve low-threshold multicolor lasers based on DJ perovskites.