Photoluminescence characteristics of microwave synthesized La2(WO4)3:Eu3+ phosphor and evaluation of its radiative parameters

Abstract

A series of Eu3+ doped La2(WO4)3 phosphors were synthesized by microwave-assisted co-precipitation technique and their properties were systematically characterized. The crystalline nature and the monoclinic structure were evidenced from the X–ray diffraction. In La2(WO4)3 host matrix, Eu3+ ions in non-centrosymmetric sites, resulting in strong and sharp peak at 615 nm (red) due to 5D0→7F2 electric dipole transition with an average short lifetime of 0.803 ms. The interesting feature of the phosphor is the delayed concentration quenching which is observed at 70 % Eu content. The radiative parameters of the phosphor analyzed in the light of Judd – Ofelt theory manifest its excellent spectral characteristics. The calculated CIE co-ordinates of the synthesized phosphors lie close to the commonly available red phosphor Y2O2S:Eu3+ and National Television System Committee (NTSC) red light standard. The above results validate the potential of Eu3+ doped La2(WO4)3 phosphor as a viable candidate for red-emitting devices.