Enhanced photoluminescence of YInGe₂O₇: Eu³⁺, Li⁺ phosphor prepared using the solid-state method

A Eu³⁺ activated YInGe₂O₇ phosphor was synthesized by solid-state reaction and lithium carbonate was added to change the morphology and photoluminescence properties. Scanning electron microscopy showed large particle size and necking shape were obtained as the concentrations of Li⁺ ions increase. In the PL studies, the excitation spectrum of YInGe₂O₇:Eu³⁺ phosphors exhibited a broad band in the UV region centered at about 272 nm attributed to charge transfer state (CTS) band, which has a little shift after Li⁺ ion was added. As the Li⁺ ion concentration increased, the photoluminescence intensity of the red emission at 620 nm of Eu³⁺ ions was enhanced, and the optimized concentration of of added Li⁺ ion is 0.05. The results showed that addition of Li⁺ ion allows YInGe₂O₇:Eu³⁺ phosphors emitting relatively pure red light.