Temperature-Dependent Steady-State and Time-Resolved Photoluminescence Spectroscopy of Cspbbr3 Encapsulated with Pbbroh and Pva

Photoluminescence (PL) intensity and stability of CsPbBr3 /PbBrOH powders are enhanced through one-pot synthesis in water. It is necessary to understand the function of PbBrOH matrix for photogenerated transition by temperature-dependent steady-state and time-resolved PL (TRPL). The enhanced PL intensity and longer lifetime indicate that the structure stability and nonradiative recombination of CsPbBr3 have significantly reduced. Negative thermal quenching is observed and interpreted with a multilevel PL transition model. The nanosecond time-resolved peak shift of PL spectra is measured under femtosecond laser excitation, the peak position shows red shift (~8 nm) with time due to the reduction of band filling effect in photoexcited carrier recombination. Then powders are further encapsulated with poly(vinyl acetate) to form a flexible film. Due to the dual protective effects of PVA and PbBrOH on CsPbBr3 , the film has excellent thermal stability. This method gives an effective inspiration in the high-quality luminous materials for application.