Preparation, electronic structure and luminescence properties of Ce3+-activated CaZnOS under UV and X-ray excitation

Abstract

The electronic structure of CaZnOS calculated using the CASTEP mode is an intermediate band gap semiconductor with a direct band gap of 2.4eV. Ce3+-activated CaZnOS samples were prepared by a solid-state reaction method at high temperature and their luminescence properties under UV–visible and X-ray excitation were investigated. CaZnOS:Ce3+ exhibits a broad band emission in the wavelength range of 450–650nm, originating from the 5d–4f transition of Ce3+ for both under blue light (460nm) and X-ray excitation. The mechanism of luminescence and concentration quenching of Ce3+ in CaZnOS have been investigated in detail. The results showed that the relative luminescence intensity reaches a maximum at 1mol% of Ce3+, and the electric dipole–dipole interaction is the major mechanism for concentration quenching of Ce3+ emission in CaZnOS. The potential application of CaZnOS:Ce3+ has been pointed out.