A Potential Red-Emitting Phosphor BaZrGe3O9:Eu3+ for WLED and FED Applications: Synthesis, Structure, and Luminescence Properties.

Abstract

A variety of Eu3+-activated BaZrGe3O9 phosphors was synthesized via solid-state reaction. The phase formation of BaZrGe3O9:Eu3+ samples was verified by powder X-ray diffraction analysis, while Rietveld refinement method was used to confirm the crystal structure. The electronic structure and characteristic photoluminescence as well as cathodoluminescence properties were researched in detail. The samples show strong absorption at 394 nm, which matches well with the commercial near-ultraviolet chips. Under 394 nm excitation, the phosphors exhibit the characteristic emissions of Eu3+ ions consistent with the 5D0-7FJ transitions. Then we investigated the thermal stability detailedly. The temperature-dependent photoluminescence emission spectra suggest that the obtained phosphors have favorable thermal stability. A white light-emitting diode (WLED) lamp with low correlated color temperature and good color render index was fabricated with blue-emitting BaMgAl10O17:Eu2+, green-emitting Sr2SiO4:Eu2+ (commercial), and red-emitting BaZrGe3O9:Eu3+ phosphors in near-ultraviolet light-emitting diodes (λmax = 395 nm) as well. Furthermore, the phosphor also exhibits red emission with high resistance and high current saturation under low voltage electron bombardment. It has better degradation resistance than the commercial Y2O3:Eu phosphor. All the results manifest that the Ba0.88Eu0.08ZrGe3O9 phosphor can be an eligible red-emitting phosphor candidate for WLEDs and field-emission displays.