Photoluminescence properties of Li2Mg2 (WO4)3:Eu3+ red phosphor with high color purity for white LEDs applications

A series of novel Eu3+ doped tungstate Li2Mg2 (WO4)3 red phosphors were successfully synthesized by a solid-state reaction method. The phase structure, photoluminescence properties and thermal stability of the phosphor were investigated in detail. The Li2Mg2 (WO4)3:Eu3+ phosphors show dominant emission peak at 620 nm (5D0→7F2 transition) upon the strongest excitation at 398 nm (7F0→5L6 transition). The optimal doping concentration of Eu3+ is determined to be 0.06 mol in order to obtain the maximum emission intensity. The dependence of the emission intensity on temperature denominates that Li2Mg2 (WO4)3:Eu3+ phosphor has a relatively good thermal quenching effect. The Commission Internationale del'Eclairage coordinates was measured as (0.678, 0.322) with high color purity, being close to the National Television Standard Committee system standard for red chromaticity (0.670, 0.330). The above studies indicate that Li2Mg2 (WO4)3:Eu3+ is a promising candidate as the red phosphor for near ultraviolet-based white LEDs application.