Luminescent properties of Ce3+ in MSO4 (M: Ca, Sr and Ba) and the effect of Na+ co-doping

Abstract The optical properties of Ce 3+ in CaSO 4 , SrSO 4 and BaSO 4 are reported. The Ce 3+ ion shows 4 f 0 5 d 1 → 2 F 5/2 , 2 F 7/2 luminescence in all three sulphates. Co-doping with Na + does not change the local surrounding of the Ce 3+ ion, but enhances the amount of Ce 3+ ions built in. Under optical excitation, besides the typical Ce 3+ doublet emission in the ultraviolet spectral region, band emission around 445 nm was observed. This band emission was not assigned to emission from a Ce 3+ centre, but to emission from an impurity-trapped exciton. Under X-ray excitation, both Ce 3+ emission and an emission band around 380 nm was observed. This band was assigned to emission from a self-trapped exciton.