Scintillation properties of composite films based on CsPbBr3 nanocrystals embedded in PMMA

Transparent composite films of polymethylmethacrylate with embedded CsPbBr3 colloidal nanocrystals (CsPbBr3-PMMA) were obtained. The optical, photoluminescent, and scintillation properties of the composite films were studied. The CsPbBr3-PMMA films had an intense photoluminescence signal and a nanosecond-range photoluminescence decay time (2 ns). The scintillation characteristics of CsPbBr3-PMMA films of different thicknesses were studied upon excitation by α-radiation of radionuclides 239Pu (Eα = 5.15 MeV) and 238Pu (Eα = 5.46 MeV). The sensitivity and minimum detectable activity of the composite films were calculated from the pulse-height spectra. The estimation of the absolute light yield according to the IEC 62372:2021 standard (determining the intrinsic resolution of scintillator) and calculation of the light collection coefficient showed that the 200-μm thick composite film emitted about 860 photons per 1 MeV of absorbed energy. Under α-excitation, the films revealed a fast scintillation response with average decay time of about 1.4 ns.