Zeitz David C, Cherrette Vivien L, Creech Sarah A, Li Yan, Ping Yuan, Zhang Jin Z
Department of Chemistry and Biochemistry, University of California, Santa Cruz, California 95064, United States.
School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, People's Republic of China.
ACS Phys Chem Au. 2024 Sep 16;4(6):610-614. doi: 10.1021/acsphyschemau.4c00051. eCollection 2024 Nov 27.
Spin relaxation of charge carriers in strongly quantum confined perovskite magic-sized clusters has been probed, for the first time, by using polarization-controlled femtosecond transient absorption (fs-TA) spectroscopy. Fs-TA measurements with a circularly polarized pump and probe allowed for the determination of the exciton spin relaxation lifetime (∼1.5 ps) at room temperature based on the dynamics of a photoinduced absorption (PIA) feature peaked at 458 nm. This spin lifetime is shorter than that of perovskite quantum dots (PQDs) with a larger size, and the results suggest that exciton confinement and defects likely play a more important role in these strongly quantum confined magic-sized clusters with a larger surface-to-volume ratio.
首次通过使用偏振控制的飞秒瞬态吸收（fs-TA）光谱，对强量子限域钙钛矿魔法尺寸团簇中电荷载流子的自旋弛豫进行了探测。利用圆偏振泵浦和探测进行的fs-TA测量，基于在458nm处达到峰值的光致吸收（PIA）特征的动力学，确定了室温下激子自旋弛豫寿命（约1.5ps）。该自旋寿命比尺寸更大的钙钛矿量子点（PQD）的自旋寿命短，结果表明，激子限域和缺陷可能在这些具有更大表面积与体积比的强量子限域魔法尺寸团簇中发挥更重要的作用。
