Low-Threshold Amplified Spontaneous Emission from Defect-Passivated Quasi-2D Perovskites

Quasi-two-dimensional (quasi-2D) perovskites demonstrate outstanding optoelectronic performance among various perovskite materials. However, to fully leverage their potential for electrically pumped lasing, careful optimization remains imperative. Exploring the domain of quasi-2D perovskite amplified spontaneous emission (ASE) holds profound significance in achieving cost-effective, solution-processable green lasers. Challenges arise from the intrinsic uneven surfaces and numerous pinholes present in pristine quasi-2D perovskite films, leading to elevated levels of optical scattering and nonradiative recombination. In this study, perovskite films with significantly improved surface morphology, optical gain properties, and ASE performance were obtained through the introduction of Tween 80 (T80) for morphology control and defect passivation. Consequently, the nonradiative recombination rate of T80-treated perovskite films experiences a 10-fold reduction. Moreover, a strikingly low ASE threshold of 3.4 μJ cm–2, accompanied by a 2-fold increase in the optical gain coefficient, has been achieved. This study demonstrates that the T80-treated quasi-2D perovskites have great promise in high-performance laser devices.