Blue emission from Sr0.98Ga2B2O7: 0.01Bi3+, 0.01Dy3+ phosphor with high quantum yield

Abstract

Most of the blue phosphors are based on Eu2+ or Ce3+ doped compounds. The luminescent centers of Eu2+ or Ce3+ generally require reducing environment during synthesis. Also, Eu2+ and Ce3+ are prone to oxidation, causing instability of the phosphors for long-term use. Herein, we report Bi3+ and Dy3+ co-doped SrGa2B2O7 blue phosphors with simpler synthesis conditions and more stable chemical property. In this phosphor, Bi3+ ions emit blue light and, while Dy3+ as sensitizer has no appreciable luminescence emission but can enhance the emission of Bi3+. Co-doping with rare earth ions enhances the emission of Bi3+, improving the efficiency and stability of the phosphor. The Sr0.98Ga2B2O7: 0.01Bi3+, 0.01Dy3+ phosphor exhibits strong blue light emission with absolute quantum yield of 65.54%. Sr0.98Ga2B2O7: 0.01Bi3+, 0.01Dy3+ has a broad excitation band (250–380 nm), emits bright blue light at 430 nm and has a narrow full width at half maxima (FWHM = 64.6 nm) with a color purity of 94.2%. Furthermore, the Sr0.98Ga2B2O7: 0.01Bi3+, 0.01Dy3+ phosphor retains strong blue light emission at high temperatures (95% at 100 °C). Overall, Sr0.98Ga2B2O7: 0.01Bi3+, 0.01Dy3+ is a promising blue emitting phosphor for n-UV WLED.