Synthesis and Photoluminescence Properties of Red-Emitting (Y, Al) VO4: Eu3+ Nanophosphors

Red-emitting Eu3+-activated (Y0.95-x Al-x) VO4 (0 < x <= 0.12) nanophosphors with the particle size of similar to 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 (Y0.95-x Al-x) VO4: Eu3+ nanophosphors were compared with those of the YVO4: Eu3+. Under 147 nm excitation, (Y-0.95-(x) Al-x) VO4 nanophosphors showed strong red luminescence due to the D-5(0)-F-7(2) transition of Eu3+ at 619 nm. The luminescence intensity of YVO4: Eu3+ enhanced with partial substitution of Al3+ for Y3+ and the maximum emission intensity was accomplished at the Al3+ content of 10 mol%. By the addition of Al3+, decay time of the (Y, Al) VO4: Eu3+ nanophosphor was decreased in comparison with that of the YVO4: Eu 3+ nanophosphor. Also, the substitution of Al3+ for Y3+ 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 similar to 80% at 600 nm.