Synthesis and luminescence properties of Eu3+-doped KLa(MoO4)2 red-emitting phosphor

Abstract

Eu3+-doped KLa(MoO4)2 phosphors were synthesized by a simple hydrothermal method. X-ray diffraction (XRD) analysis demonstrated that the as-prepared products were pure monoclinic phase of KLa(MoO4)2. Field emission scanning electron microscopy (FE-SEM) images indicated that the morphology of the prepared phosphors evolved from uniform spherical-like to irregular elliposid-like with increase of the concentration. The photoluminescence (PL) spectra displayed that the phosphors show strong red light around 618nm, attributed to 5D0→7F2 transition of Eu3+ ion under 465nm excitation, and the optimal Eu3+ doping concentration was about 15mol.% based on the concentration dependent emission spectra. According to Dexter’s theory the electric dipole–dipole interaction (D–D) is the main mechanism for energy transfer between Eu3+ and Eu3+ ions. The CIE chromaticity (x, y) of the phosphors were about (0.65, 0.35) and it is close to the standard red chromaticity of NTSC. Therefore, the phosphors could be used as red phosphors for white light-emitting diodes.