Preparation and near-white luminescence properties of Bi3+ doped and Bi3+/Eu3+ co-doped germanate phosphor powder

The Bi3+ doped and the Bi3+/Eu3+ co-doped germanate phosphor powders were synthesized by high-temperature solid-state reaction and their luminescence properties were investigated. The XRD analysis results show that the crystalline phase of all samples is the tetragonal phase of BaGeO3. The Bi3+ doped BaGeO3 phosphors exhibited an intense near-white light emission and the wavelength of the luminescence center was located at 466 nm. The Bi3+ doped BaGeO3 phosphors can be efficiently excited by the incident light of 260–430 nm. The tunability of the emission color can be achieved by changing the Bi3+ ion doping concentration and the high-temperature sintering time. The Bi3+/Eu3+ co-doped BaGeO3 phosphors exhibited an intense red emission and the wavelength of the luminescence center was located from 466 to 705 nm. The Bi3+/ Eu3+ co-doped BaGeO3 phosphors can be efficiently excited by the incident light of 312–532 nm. The emission color tunability can be obtained by changing the Eu3+ ions doping concentration and the wavelength of excitation. The visible region emission characteristics of BaGeO3:Bi3+, Bi3+/Eu3+ indicate that it can potentially be used as a new efficient near-white luminescent material.