标题： 热载流子捕获保持了高量子产率，但限制了基于InP的量子点中的光学增益 显示英文标题

标题： Hot-carrier trapping preserves high quantum yields but limits optical gain in InP-based quantum dots

摘要： 磷化铟是胶体量子点商业应用的首选材料。 然而到目前为止，该领域尚未在强激发条件下实现成功运行，这与其他材料形成了鲜明对比。 在此，我们报告了最先进的基于磷化铟的量子点的异常光物理特性，使其作为增益材料不具吸引力。 结合从飞秒到微秒时间尺度的基于群体的时间分辨光谱学和单量子点光谱学，揭示了热载流子的超快捕获过程。 这一过程导致载流子损失，从而降低了可实现的粒子数反转，限制了增益材料中光的放大。 有趣的是，荧光仅被延迟，而不是被猝灭，这解释了为什么基于磷化铟的量子点在低强度应用中作为明亮的发光颜色转换器是成功的。 与其他流行的量子点材料（如CdSe、铅卤钙钛矿和CuInS2）的比较表明，观察到的热载流子动力学是磷化铟特有的。 显示英文摘要

摘要： Indium phosphide is the leading material for commercial applications of colloidal quantum dots. To date, however, the community has failed to achieve successful operation under strong excitation conditions, contrasting sharply with other materials. Here, we report how the unusual photophysics of state-of-the-art InP-based quantum dots make them unattractive as a gain material. A combination of ensemble-based time-resolved spectroscopy over timescales from femtoseconds to microseconds and single-quantum-dot spectroscopy reveals ultrafast trapping of hot charge carriers. This process leads to charge-carrier losses, thereby reducing the achievable population inversion which limits amplification of light in a gain material. Interestingly, fluorescence is only delayed, not quenched, by hot charge-carrier trapping, explaining why InP-based quantum dots are successful as bright luminescent colour convertors for low-intensity applications. Comparison with other popular quantum-dot materials, such as CdSe, Pb-halide perovskites, and CuInS2, indicate that the hot-carrier dynamics observed are unique to InP.