Quartet Aggd (wo <sub> 4 </ Sub>) <sub> 2 </ Sub>: Eu <sup> 3 + </ Sup> Preparation Of Red Phosphor

White Light-emitting diode (WLED) as the one of hopeful green illumination light source has extensively applied in solid-state lighting, due to its lots of advantages, such as high efficacy, energy saving, and envirnment-friendly. The mainstream scheme to abtain WLED is phosphor conversion. However, the current red phosphors used for WLED displays a rather low efficient emission under near-UV light excitation. So prepare red phosphors with highly-efficientunder excitation of near-UV light is the biggest problem for WLED. In this work, a new red phosphor AgGd(WO4)2:Eu3+ was prepared by solid-state reaction. The influence of temperature on the luminescent properties and structure was discussed. Two method, codoping Mo6+ in matrix and energy transfer between sensitizer Tb3+ and Eu3+, were adoped to improve the luminescent properties of AgGd(WO4)2:Eu3+.AgGd(WO4)2:Eu3+ was synthesized by solid-state reaction in the temperature range of 750～1100℃. AgGd(WO4)2 has two homogenous structures, monocline phase and tetragonal phase. Whereas, the tetragonal phase AgGd(WO4)2 was not reported in literatures. The PL results showed that AgGd(WO4)2:Eu3+ was a red phosphor, which could be used in near-UV and blue light LED. The emission intensity of AgGd(WO4)2:Eu3+ was affected by annealing temperature. Additionally, the emission intensity of the tetragonal phase was higher than the monocline phase AgGd(WO4)2:Eu3+.In order to improve the luminescent properties of AgGd(WO4)2:Eu3+, Mo6+ ions was doped in AgGd(WO4)2:Eu3+. The results indicated that the structure of AgGd(WO4)2 was not changed, while the lattice volume of which was decreased and the emission intensity was enhanced with the increase of Mo6+.The second method was taked to improve the AgGd(WO4)2:Eu3+. The sensitizer Tb3+ was co-doped to enhance the PL intensity of AgGd(WO4)2:Eu3+. Characteristic emission of Tb3+ can be detected in AgGd(WO4)2:Tb3+ and AgGd(W0.7Mo0.3O4)2:Tb3+. For the AgGd(WO4)2:Eu3+,Tb3+ and AgGd(W0.7Mo0.3O4)2:Eu3+,Tb3+, the energy transfer from Tb3+to Eu3+can be measured. However, the energy transfer efficiency of AgGd(W0.7Mo0.3O4)2:Eu3+, Tb3+ was higher than that of AgGd(WO4)2:Eu3+,Tb3+.