The Environmental Stability of CsPbBr<sub>3</sub> PQD\nThin-Film Scintillators with Encapsulants

CsPbBr<sub>3</sub> perovskite quantum dots (PQDs) are promising\ncandidates for scintillator materials due to their tunable emission\nwavelength, high light yield, high atomic number, and low cost. However,\ntheir poor environmental stability hinders further practical applications.\nHerein, CsPbBr<sub>3</sub> PQD thin film scintillators are encapsulated\nwith selected PMMA, PS, and ER with different thicknesses using the\nspin-coating method. Photoluminescence spectroscopy is employed to\nevaluate the light output affected by environmental stability. The\nresults indicated that the PS film outperforms the other two encapsulants\nin the thermal stability tests at 100 °C and humidity stability\ntests at relative humidity levels of 95–100%. In particular,\nthe thick PS film, measuring 34.49 μm, demonstrates excellent\nenvironmental stability, while the thicknesses of the films ranging\nfrom 1.44 to 34.5 μm do not influence the light output of the\nCsPbBr<sub>3</sub> PQD thin-film scintillators, a finding that is\ncorroborated by simulations. This work has significant implications\nfor the practical application of all-inorganic perovskite scintillators\nin ionizing radiation detection.