Organic-inorganic lead halide quasi-two-dimensional (2D) perovskites are promising gain media for lasing applications because of their low cost, tunable colour, excellent stability and solution processability1-3. Optically pumped continuous-wave (CW) lasing is highly desired for practical applications in high-density integrated optoelectronics devices and constitutes a key step towards electrically pumped lasers4-6. However, CW lasing has not yet been realized at room temperature because of the 'lasing death' phenomenon (the abrupt termination of lasing under CW optical pumping), the cause of which remains unknown. Here we study lead halide-based quasi-2D perovskite films with different organic cations and observe that long-lived triplet excitons considerably impede population inversion during amplified spontaneous emission and optically pumped pulsed and CW lasing. Our results indicate that singlet-triplet exciton annihilation is a possible intrinsic mechanism causing lasing death. By using a distributed-feedback cavity with a high quality factor and applying triplet management strategies, we achieve stable green quasi-2D perovskite lasers under CW optical pumping in air at room temperature. We expect that our findings will pave the way to the realization of future current-injection perovskite lasers.

中文翻译：

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准二维钙钛矿薄膜中稳定的室温连续波激光

有机-无机卤化铅准二维 (2D) 钙钛矿因其低成本、可调颜色、出色的稳定性和溶液加工性而成为用于激光应用的有前途的增益介质 1-3。光泵浦连续波 (CW) 激光在高密度集成光电子器件的实际应用中非常受欢迎，并且是迈向电泵浦激光器的关键步骤 4-6。然而，由于“激光死亡”现象（CW光泵浦下激光突然终止），CW激光在室温下尚未实现，其原因尚不清楚。在这里，我们研究了具有不同有机阳离子的基于卤化物的准二维钙钛矿薄膜，并观察到长寿命的三线态激子在放大的自发发射和光泵浦脉冲和连续激光发射过程中显着阻碍了粒子数反转。我们的结果表明，单线态-三线态激子湮灭可能是导致激光死亡的内在机制。通过使用具有高质量因子的分布式反馈腔并应用三重态管理策略，我们在室温空气中的连续光泵浦下实现了稳定的绿色准二维钙钛矿激光器。我们希望我们的发现将为实现未来的电流注入钙钛矿激光器铺平道路。通过使用具有高质量因子的分布式反馈腔并应用三重态管理策略，我们在室温空气中的连续光泵浦下实现了稳定的绿色准二维钙钛矿激光器。我们希望我们的发现将为实现未来的电流注入钙钛矿激光器铺平道路。通过使用具有高质量因子的分布式反馈腔并应用三重态管理策略，我们在室温空气中的连续光泵浦下实现了稳定的绿色准二维钙钛矿激光器。我们希望我们的发现将为实现未来的电流注入钙钛矿激光器铺平道路。