Effect of Bi3+ions on the enhanced luminescent properties of novel red-emitting Sr3Ga2Ge4O14: Eu3+phosphors

A series of novel red-emitting Sr3-xGa2Ge4O14: xEu3+ (x = 0-0.50) and Sr3-x-yGa2Ge4O14: xEu3+, yBi3+ (x = 0.30, y = 0-0.07) phosphors have been synthesized through a high-temperature solid-state method. The materials were characterized by X-ray diffraction, scanning electron microcopy, energy-dispersive spectra, diffuse reflec-tion spectra, luminescence properties, luminescence decay curves, and thermal properties. The introduction of Bi3+ ions can greatly affect the thermal and luminescent properties of Sr3Ga2Ge4O14: Eu3+ phosphor. The in-ternal quantum efficiency and color purity of Sr0.265Ga2Ge4O14: 0.30Eu3+, 0.05Bi3+ sample were measured to be 49.4% and 99.9% respectively. Using the as-synthesized Sr0.265Ga2Ge4O14: 0.30Eu3+, 0.05Bi3+ phosphors as red component, a high-performance white LED with 5489K correlated color temperature and Ra = 88.2 color -rendering index has been fabricated with a 395 nm near-UV chip, commercial green (Ba,Sr)2SiO4: Eu2+ and blue BaMgAl10O17: Eu2+ phosphors. The results indicated that the as-synthesized Sr3Ga2Ge4O14: Eu3+, Bi3+ phosphor may serve as potential high-efficiency red-emitting material for white light-emitting-diodes.