Synthesis and luminescent properties of Mn4+-doped Li2.06Nb0.18Ti0.76O3 high color purity red-emission phosphor

A series of Mn4+-doped Li2.06Nb0.18Ti0.76O3 red-emission phosphors were triumphantly constructed via the solid-state reaction (SSR) route. X-ray diffractometers, electron microscope, spectrophotometer, and the absolute QY measurement instrument were used to research the structure, surface topography, and luminous performance of the phosphor. All the phosphors prepared are Li2TiO3 solid solution phase, and the powder sizes are 0.5–1 μm. The optimum synthesis temperature of Li2.06Nb0.18Ti0.76O3: xMn4+ is 900 °C, which is lower than the temperature of nitrides phosphors. Excitation at 342 nm, the phosphor presents narrow and strong emission bands centered at ∼685 nm, with an absolute quantum yield of about 26.1%. The Tanabe-Sugano diagram is used to investigate the luminescence mechanism. The lifetime of the Li2.06Nb0.18Ti0.755O3: 0.005Mn4+ phosphor is 0.245 ms. Furthermore, Li2.06Nb0.18Ti0.76O3: Mn4+ red-emitting phosphors possess a high-color purity reached 98.5%, and the values of CCT and CIE coordinates were calculated to be 4899 K, and (0.7287, 0.2713), respectively. The results demonstrate the potential of Li2.06Nb0.18Ti0.76-xO3: xMn4+ phosphors for white LED applications.