The photon flux-dependent transient absorption spectroscopy is employed to investigate the carrier dynamics of Cs₂AgBiBr₆ nanocrystals (NCs), exhibiting that the hot carrier cooling, the self-trapping process, the surface defect capture and the carrier recombination together participate in the carrier relaxation process after photoexcitation. The evolution of their lifetimes as a function of 〈N〉 (average photon number per nanocrystal) all show two stages. Moreover, the role of HC in the subsequent carrier dynamics is also discussed. These results can help explain the carrier dynamics in the double perovskite NCs for designing and optimizing the perovskite-based optoelectronic devices with high performance.

采用光子通量相关瞬态吸收光谱研究 Cs ₂ AgBiBr ₆纳米晶体 (NCs)的载流子动力学，表明热载流子冷却、自陷过程、表面缺陷捕获和载流子复合共同参与了光激发后的载流子弛豫过程。它们的寿命随<N>（每个纳米晶体的平均光子数）的演变都显示出两个阶段。此外，还讨论了 HC 在随后的载流子动力学中的作用。这些结果有助于解释双钙钛矿 NC 中的载流子动力学，以设计和优化高性能的基于钙钛矿的光电器件。