The Environmental Stability of CsPbBr3 PQD Thin-Film Scintillators with Encapsulants

CsPbBr3 perovskite quantum dots (PQDs) are promising candidates for scintillator materials due to their tunable emission wavelength, high light yield, high atomic number, and low cost. However, their poor environmental stability hinders further practical applications. Herein, CsPbBr3 PQD thin film scintillators are encapsulated with selected PMMA, PS, and ER with different thicknesses using the spin-coating method. Photoluminescence spectroscopy is employed to evaluate the light output affected by environmental stability. The results indicated that the PS film outperforms the other two encapsulants in the thermal stability tests at 100 °C and humidity stability tests at relative humidity levels of 95–100%. In particular, the thick PS film, measuring 34.49 μm, demonstrates excellent environmental stability, while the thicknesses of the films ranging from 1.44 to 34.5 μm do not influence the light output of the CsPbBr3 PQD thin-film scintillators, a finding that is corroborated by simulations. This work has significant implications for the practical application of all-inorganic perovskite scintillators in ionizing radiation detection.