The preparation and luminescence of Lu2O2S:Ce3+

Lu2O2S:Ce phosphors have been prepared by oxalate coprecipitation first and then solid state reaction at 1150 °C in reducing atmosphere. XRD pattern indicates that the sample is pure hexagonal structure (space group image, lattice constant image, image). Under UV or blue excitation, a red broad emission can be observed at room temperature, and such an emission spectrum (peak at 650 nm, with full-width of half-maximum (FWHM) 200 nm) can be resolved by Gauss fit into two, with peaks at 619 and 706 nm, corresponding to the transition of 5d state to 4f2F5/2 and 2F7/2 of Ce3+ ion, respectively. Photoluminescence excitation (PLE) and diffuse reflectance spectra show that a host excitation exists in the range shorter than 280 nm and a 4f–5d excitation is in the band with peak at 460 nm. Photoluminescence and PLE spectra varying with Ce3+ concentration as well as their mechanism have also been studied.