A Novel Blue-emitting Sr2Gd8(SiO4)6O2:Bi3+ Phosphor with Oxyapatite Structure

Abstract A series of Sr2Gd8(SiO4)6O2 (SGSO):xBi3+ (x = 0.005, 0.007, 0.010, 0.030 and 0.050) phosphors were successfully synthesized by a high-temperature solid-phase route. The X-ray powder diffraction (XRD), scanning electron microscopy (SEM), fourier transform infrared (FT-IR), ultraviolet-visible diffuse reflectance (UV-Vis DR), photoluminescence excitation (PLE) and emission (PL) spectra were utilized to evaluate the samples. The characterization results show that the PLE spectra monitored at 440 nm present a broad band with the maximum at 315 nm. Besides, the pure SGSO possesses the space group P63/m crystal structure, in which the low symmetry C3 or Cs sites favor the transition from 3P1 to 1S0 of Bi3+, thus produce strong blue emission. According to the calculation of concentration quenching, the critical distance of energy transfer (ET) between adjacent Bi3+ is 23.48 A, and it is concluded that the quenching mechanism is attributed to d-d interaction. Eventually, the International Commission on Illumination (CIE) chromaticity coordinates of phosphors are located in blue region, which can be suitable for practical application in the field of the white light-emitting diode (WLED) and plasma display panels (PDPs).