In colloidal quantum dots (QDs), excitons are confined within nanoscale dimensions, and the relaxation of hot electrons occurs through Auger cooling. The behavior of hot electrons is evident under ambient pressure. Nanocrystal characteristics, including their size, are key to determining hot electron behavior because they serve as the stage. Applying pressure to materials can effectively modify this stage by providing a means to reversibly control interatomic distances. Unlike the behavior under ambient conditions, the pressure-dependent behavior remains unclear. In this study, InP/ZnS QDs were synthesized, and their pressure-dependent ultrafast carrier dynamics were analyzed using fs-transient absorption spectroscopy. The hot electron relaxation remained nearly constant up to the threshold pressure, suggesting constant interaction between electrons and holes. However, above this threshold, the hot electron relaxation was accelerated by trapping from higher excited states. This study contributes to establishing a fundamental understanding of the pressure-dependent behavior of hot electrons in QDs.

中文翻译：

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外加压力下 InP/ZnS 量子点的基本激子过程


在胶体量子点 （QD） 中，激子被限制在纳米级维度内，热电子的弛豫是通过俄歇冷却发生的。热电子的行为在环境压力下很明显。纳米晶体特性（包括它们的尺寸）是决定热电子行为的关键，因为它们充当舞台。对材料施加压力可以通过提供一种可逆地控制原子间距离的方法来有效地改变这个阶段。与环境条件下的行为不同，压力相关行为仍然不清楚。在本研究中，合成了 InP/ZnS QDs，并使用 fs-transient absorption 光谱分析了它们的压力依赖性超快载流子动力学。热电子弛豫在阈值压力之前几乎保持恒定，表明电子和空穴之间存在恒定的相互作用。然而，高于这个阈值，热电子弛豫会因从较高激发态捕获而加速。这项研究有助于建立对 QD 中热电子的压力依赖性行为的基本理解。