Photoluminescence properties and crystal structure of BaSiO3:xEu(3+), yBi(3+)red phosphor synthesized by co-precipitation method

摘要

The Ba1-xSiO3:xEu(3+) (x = 0.0025, 0.02, 0.04, 0.06, 0.08, 0.09), Ba0.996SiO3:0.004Bi(3+) and Ba0.92-ySiO3:0.08Eu(3+),yBi(3+),yBi(3+) (y = 0, 0.001, 0.0025, 0.004, 0.005, 0.01) phosphors have been synthesized by chemical co-precipitation method combined with one calcination of the corresponding precursors in air. Then the XRD, XPS and spectrophotometer have been carried out to analyze the crystal structure and photoluminescence properties of the phosphor. The structure of samples is orthorhombic and the space group is P2(1)2(1)2(1). Meanwhile, Bi3+ co-doped system shows a broadened charge transfer band (CTB) and the highest peak of CTB has red shifted from 246 to 274 nm due to an overlap of the transition from O-2- to Bi3+. The symmetry of Eu3+ ions is distorted by co-doping Bi3+ ion and the efficient energy transfer from Bi3+ to Eu3+ ions enhances the photoluminescence intensities of the BaSiO3:Eu3+, Be3+ phosphors significantly. The optimum concentration of Eu3+ and Be3+ ions in BaSiO3 is 8 mol% and 0.4 mol%, respectively. Additionally, the CIE 1931 chromaticity coordinates of Ba0.916SiO3:0.08Eu(3+), 0.004Bi(3+) excited by 274 and 393 nm are located at red region. The PL emission spectra of the optimized phosphor at different temperatures show an excellent thermal stability, it remains 87.6% of photoluminescence intensity at 25 degrees C when the temperature reaches 100 degrees C. Moreover, the activation energy (Ea) is calculated to be 0.27 eV. These results indicate that BaSiO3:Eu3+, BP3+ phosphors are the suitable candidates for commercial red phosphor.