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

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.