Afterglow phosphor materials Y2O2S: Eu, Mg, Ti doped with various Gd concentrations

Red afterglow phosphors Y2O2S with 5 mol% Eu, 2 mol% Mg, 4 mol% Ti (fixed) and various Gd ion concentrations (0–3 mol%) were prepared by solid state reaction method. The phase compositions of the obtained phosphor were characterized by powder X-ray diffraction (XRD) method. The surface morphology and the particle size were observed by scanning electron microscopy (SEM). Luminescent properties were investigated by measuring emission spectra, excitation spectra and decay curves. The results indicated that the major phase with various doped Gd ion concentrations was not changed, the intense red emission was observed for the Y2O2S: Eu, Mg, Ti, Gd phosphor (λmax = 626 nm). The Gd ion doping may change the trap depth in the Y2O2S matrix and improve the luminescent properties of the samples. The optimized Gd ion concentration of the red afterglow phosphor is 1 mol%. The stability of the phosphor with respect to the air and humidity were also explored.