Comparative analysis of LiGd(WO4)2:Eu3+ phosphors derived by sol gel and hydrothermal methods

LiGd(WO4)2 (LGW): Eu3+ red phosphors were prepared by sol gel and hydrothermal methods. The crystallization, particle morphology and luminescent properties of the LGW:Eu3+ phosphors were investigated. The powder X ray diffraction (pXRD) results confirm the single phase tetragonal structure. The scanning electron microscope (SEM) images reveal sphere like and spindle like microcrystal of the samples prepared by sol gel and hydrothermal methods respectively. The excitation spectrum shows a broader band at the lower wavelength region due to the charge transfer band [CTB] of O2- → Eu3+ and O2- → W6+ transitions and sharper peaks at the higher wavelength region due to the f-f transition bands of the Eu3+ ions. The strong and intense red emission peak at 615 nm for 5D0 → 7F2 transition was observed under near UV excitation. Hydrothermally synthesized LGW:Eu3+ phosphors exhibit higher CTB and stronger red emission intensity at 615 nm than sol gel synthesized phosphors.