Lv Yan, Yin Chunyang, Zhang Chunfeng, Wang Xiaoyong, Yu Zhi-Gang, Xiao Min
National Laboratory of Solid State Microstructures, School of Physics, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, China.
ISP/Applied Sciences Laboratory, Washington State University, Spokane, WA, 99210, USA.
Nat Commun. 2021 Apr 13;12(1):2192. doi: 10.1038/s41467-021-22486-5.
Single perovskite nanocrystals have attracted great research attention very recently due to their potential quantum-information applications, which critically depend on the development of powerful optical techniques to resolve delicate exciton photophysics. Here we have realized resonant and near-resonant excitations of single perovskite CsPbI nanocrystals, with the scattered laser light contributing to only ~10% of the total collected signals. This allows us to estimate an ultranarrow photoluminescence excitation linewidth of ~11.32 µeV for the emission state of a single CsPbI nanocrystal, corresponding to an exciton dephasing time of ~116.29 ps. Meanwhile, size-quantized acoustic phonons can be resolved from a single CsPbI nanocrystal, whose coupling with the exciton is proposed to arise from the piezoelectric potential. The ability to collect resonance fluorescence from single CsPbI nanocrystals, with the subsequent revelation of exciton-acoustic phonon coupling, has marked a critical step towards their steady advancement into superior quantum-light sources.
单钙钛矿纳米晶体因其潜在的量子信息应用，最近引起了极大的研究关注，而这些应用严重依赖于强大光学技术的发展来解析精细的激子光物理过程。在此，我们实现了单钙钛矿CsPbI纳米晶体的共振和近共振激发，散射激光光仅占总收集信号的约10%。这使我们能够估计单个CsPbI纳米晶体发射态的超窄光致发光激发线宽约为11.32 μeV，对应激子退相时间约为116.29 ps。同时，尺寸量子化的声子可从单个CsPbI纳米晶体中分辨出来，其与激子的耦合被认为源于压电势。从单个CsPbI纳米晶体收集共振荧光的能力，以及随后激子 - 声子耦合的揭示，标志着它们朝着成为卓越量子光源稳步前进的关键一步。
