This study aims to achieve an ultralow lasing threshold in CsPbBr₃ microplates (MPs), a crucial step toward developing electrically driven micro/nanolasers for optics integrated chips. We investigate the lasing behavior of CsPbBr₃ MPs under varying pressures by using static-state photoluminescence (PL), time-resolved PL (TRPL), and first-principles theory calculations based on density functional theory (DFT). Our results reveal that the lasing threshold initially decreases and then increases, with a critical turning point at 0.44 GPa. Notably, we achieve an optimal lasing threshold of 20.87 μJ/cm² after releasing pressure from 1.87 GPa, highlighting the potential of pressure modulation to optimize the lasing performance. At low pressure, pressure-induced phonon hardening enhances the barrier, preventing excitons decay from free states to trapping states. Conversely, at higher pressure, the increased density of surface defects, due to pressure-induced anisotropic contraction of lattice constants along the c-axis, leads to excitons decay from free states to trapping states. For CsPbBr₃ MPs, it is evident that only free excitons contribute to lasing, while both free and trapped excitons contribute to luminescence. These findings offer a novel strategy to optimize the lasing performance of perovskite micro/nanolasers, significantly advancing their potential for practical applications in optoelectronic devices.

中文翻译：

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通过压力调节激子复合动力学来优化 CsPbBr3 微孔板的激光处理性能


本研究旨在在 CsPbBr₃ 微孔板 （MPs） 中实现超低激光阈值，这是开发用于光学集成芯片的电驱动微/纳米激光器的关键一步。我们使用静态光致发光 （PL）、时间分辨 PL （TRPL） 和基于密度泛函理论 （DFT） 的第一性原理理论计算研究了 CsPbBr₃ MPs 在不同压力下的激光行为。我们的结果表明，激光阈值最初降低后增加，临界转折点为 0.44 GPa。值得注意的是，在从 1.87 GPa 释放压力后，我们实现了 20.87 μJ/cm² 的最佳激光阈值，这凸显了压力调制优化激光性能的潜力。在低压下，压力诱导的声子硬化增强了势垒，防止激子从自由态衰变为俘获态。相反，在较高压力下，由于压力诱导的晶格常数沿 c 轴的各向异性收缩，表面缺陷的密度增加，导致激子从自由态衰变为俘获态。对于 CsPbBr₃ MP，很明显，只有游离激子有助于激光，而游离激子和俘获激子都有助于发光。这些发现为优化钙钛矿微/纳米激光器的激光性能提供了一种新策略，显着提高了它们在光电器件中的实际应用潜力。