Ming Mei, Minju Kim, Sang Hyuk Park, Ga Eul Choi, Songyi Lee, Robert A. Taylor, Wei Chen, Suck Won Hong, Kwangseuk Kyhm
The temperature-dependent photoluminescence of CsPbBr3/SiO2 and CsPbI3/SiO2 nanocrystals was investigated to understand the thermal stability of SiO2 encapsulation. At increased temperature, intensity quenching, linewidth broadening, energy level shift, and decay dynamics were evaluated as quantified parameters. Comprehensive analysis of these parameters supports that CsPbI3/SiO2 nanocrystals show a stronger interaction with phonons compared with CsPbBr3/SiO2 nanocrystals. Despite SiO2 encapsulation, we conclude that trapping states are still present and the degree of localization can be characterized in terms of short-lived decay time and thermal activation energy.