Luminescence and scintillation properties of Ce-doped Cs₂ZnCl₄ crystals

In this study, we have synthesized scintillation materials based on Ce-doped Cs₂ZnCl₄ crystals. The light yield was enhanced by up to 20% by doping Cs₂ZnCl₄ with Ce³⁺ ions. In the scintillation time profiles, fast components exhibited decay time constants on the order of nanoseconds, which was ascribed to Auger-free luminescence (AFL). The light yield of the AFL component decreased at 10 mol% Ce³⁺ concentration, which is mainly attributed to the reabsorption of AFL photons inside the crystals by Ce³⁺ ions, as seen in the scintillation spectra. Long components had decay time constants of approximately 30 ns. In addition, at 10 mol% Ce³⁺ concentration, a prominent band appeared at approximately 500 nm in the scintillation spectrum, which was not observed in the photoluminescence spectra. The long components in the scintillation time profiles and the 500 nm band in the scintillation spectra were tentatively attributed to self-trapped excitons perturbed by Ce³⁺ ions.