Yu Buyang, Zhang Chunfeng, Chen Lan, Huang Xinyu, Qin Zhengyuan, Wang Xiaoyong, Xiao Min
National Laboratory of Solid State Microstructures, School of Physics, and Collaborative Innovation Center for Advanced Microstructures, Nanjing University, Nanjing 210093, China.
Department of Physics, University of Arkansas, Fayetteville, Arkansas 72701, USA.
J Chem Phys. 2021 Jun 7;154(21):214502. doi: 10.1063/5.0051611.
Quantum dephasing of excitonic transitions in CsPbBr nanocrystals has been studied using two-dimensional electronic spectroscopy at cryogenic temperatures. The exciton-phonon interactions for acoustic and optical modes exhibit different effects on the coherent dynamics of excitonic transitions. The homogeneous linewidth shows a proportional dependence on the temperature, suggesting the primary dephasing channel of the elastic scattering between exciton and acoustic modes. The exciton-optical mode interaction is manifested as the beatings of off-diagonal signals in the population time domain at the frequencies of 29 and 51 cm, indicating phonon replicas of excitonic transitions arising from coherent exciton-phonon interaction. The insight information of exciton homogeneous broadening in perovskite nanocrystals is essential for the potential application of quantum light sources.
利用低温二维电子光谱研究了CsPbBr纳米晶体中激子跃迁的量子退相。声学和光学模式的激子-声子相互作用对激子跃迁的相干动力学表现出不同的影响。均匀线宽显示出与温度成比例的依赖性，这表明激子与声学模式之间弹性散射是主要的退相通道。激子-光学模式相互作用表现为在29和51厘米频率处的布居时域中非对角信号的拍频，表明相干激子-声子相互作用产生了激子跃迁的声子复制品。钙钛矿纳米晶体中激子均匀展宽的深入信息对于量子光源的潜在应用至关重要。
