Photoluminescence of ZnGa2O4:: Mn phosphor fired at vacuum atmosphere

The ZnGa2O4 phosphor doped with Mn2+ was fired from the mixed of ZnO and Ga2O3, the effects of firing conditions and the emission characteristics were investigated. Zn1-xMnxGa2O4 phosphors fired at air atmosphere, exhibits two emission bands with main peak at 506 nm (Mn2+ emission center) and weak peak at 666 nm (Mn4+ emission center). However, where as fired at vacuum atmosphere, the emission spectrum shown only 506 nm peak, and its intensity increase drastically. From its excitation spectrum, apart from 245 nm (the absorption peak of ZnGa2O4), there are two absorption peaks (304 and 626 nm) which derived from Mn2+, these spectra fit the energy levels of T-4(1) (4P) and T-4(1) (4G) during Mn2+ (3d(5)) split. The green emission band of 506 nm can be excited by such a absorption peak, the highest intensity is provoked by 304 nm. The emission intensity of Zn1-xMnxGa2O4 phosphors of 506 nm peak are strongest when firing in 10(-2) Torr vacuum atmosphere at 1300 degrees C, 1.5 h and Mn2+ concentration is x = 0.006. (C) 1999 Elsevier Science Limited and Techna S.r.l. All rights reserved.