Synthesis and photoluminescence properties of red-emitting (Y,Al)VO ₄: Eu ³⁺ nanophosphors

Red-emitting EU ³⁺-activated (Y _0.95-sAl _s)VO ₄ (0 < × ≤ 0.12) nanophosphors with the particle size of ~30 nm and the high crystallinity have been successfully synthesized by a hydrothermal reaction. In the synthetic process, deionized water as a solvent and ethylene glycol as a capping agent were used. The crystalline phase, particle morphology, and the photoluminescence properties of the excitation spectrum, emission intensity, color coordinates and decay time, of the prepared (Y _0.95-sAl _s)VO ₄:Eu ³⁺ nanophosphors were compared with those of the YVO ₄:Eu ³⁺. Under 147 nm excitation, (Y _0.95-sAl _s)VO ₄ nanophosphors showed strong red luminescence due to the $ transition of Eu ³⁺ at 619 nm. The luminescence intensity of YVO ₄:Eu ³⁺ enhanced with partial substitution of Al ³⁺ for Y ³⁺ and the maximum emission intensity was accomplished at the Al ³⁺ content of 10 mol%. By the addition of Al ³⁺, decay time of the (Y ₁Al)VO ₄:Eu ³⁺ nanophosphor was decreased in comparison with that of the YVO ₄:Eu ³⁺ nanophosphor. Also, the substitution of Al ³⁺ for Y ³⁺ invited the improvement of color coordinates due to the increase of R/O ratio in emission intensity. For the formation of transparent layer, the red nanophosphors were fabricated to the paste with ethyl celluloses, anhydrous terpineol, ethanol and deionized water.By screen printing method, a transparent red phosphor layer was formed onto a glass substrate from the paste. The transparent red phosphor layer exhibited the red emission at 619 nm under 147 nm excitation and the transmittance of ~80% at 600 nm.