Tunable luminescence properties of GeO2-Doped Li2ZnTi3O8: Mn4+ red phosphor

Abstract

Ab initio calculation of density of states and the absorption spectral analysis were performed, and the influence of doping Mn4+ activator and Ge4+ sensitizer on the photoluminescence properties was also successfully discussed. The critical concentrations of Mn4+ and Ge4+ in Li2ZnTi3O8 host excited at 350 nm were determined to be 0.3 and 0.4 %, respectively. The results obtained in this study indicated that there was a 50 % promotion in the emission intensity in the 0.4 % GeO2-doped phosphors when compared to the performance of undoped Li2ZnTi3O8: 0.3 % Mn4+ phosphors. Moreover, the International Commission on Illumination of Li2ZnTi3O8:0.3 % Mn4+ point was successfully turned from (0.7268, 0.2732) to (0.7318, 0.2682), and the color purity - from 98.3 to 99.5 % by co-doping 0.4 % GeO2. The energy transfer mechanism (Mn4+---Mn4+ pairs, and Ge4+---Mn4+ pairs) was also investigated. Concentration and thermal quench were also under consideration.