Photophysical Properties of Zn-Alloyed CsPbI<sub>3</sub> Nanocrystals
Fuli Zhao, Junzi Li, Jiahao Yu, Zhihang Guo, Shuyu Xiao, Yang Gao, Ruikun Pan, Tingchao He, Rui Chen
Abstract
Deep-red luminescence emission makes CsPbI3 nanocrystals (NCs) promising materials for various applications, but their use is limited in practice by instability in moist ambient environments. Incorporating Zn into CsPbI3 NCs can help retain crystallinity and improve moisture resistance and device performance. However, a fundamental understanding of the photophysical properties of Zn-alloyed CsPbI3 NCs remains incomplete. In this study, the differences in the photophysical properties of CsPbI3 NCs and their Zn-alloyed counterparts (CsPb0.8Zn0.2I3 NCs) are highlighted. Femtosecond transient absorption spectroscopy experiments show that the rate of carrier cooling is higher in CsPb0.8Zn0.2I3 NCs than in CsPbI3 NCs, whereas the two types of NCs exhibit similar Auger recombination lifetimes and biexcition binding energies. Our experimental results show more efficient multiphoton absorption by CsPb0.8Zn0.2I3 NCs than by CsPbI3 NCs. This result implies that Zn-alloyed CsPbI3 NCs are promising materials for multiphoton-excited emission-relevant applications.