Temperature-dependent surface plasmon enhanced photoluminescence in CsPbBr3 thin film

In this paper, we report CsPbBr3/SiO2/Ag hybrid thin films structure to realize the metal surface plasmon enhanced photoluminescence. The photoluminescence of CsPbBr3 can be enhanced when the CsPbBr3 excitons interact with surface plasmon from Ag thin film. The numerical simulation demonstrates the localized electric field induced by surface plasmon is the strongest when SiO2 interlayer has the thickness of 5 nm. If taking account of the energy transfer from CsPbBr3 excitons to Ag layer, the experimental maximum photoluminescence enhancement factor actually occurs when the SiO2 thin film has a thickness of 20 nm. The temperature-dependent photoluminescence demonstrates that metal surface plasmon enhanced photoluminescence has higher enhancement factor at lower temperature, which is attributed to the stronger surface plasmon coupling efficiency at low temperature. The time-resolved photoluminescence further proves that the surface plasmon coupling can enhance the spontaneous emission rate at low temperature.