Synthesis and luminescence properties of a La2W3O12:Eu3+ phosphor for near-UV white LEDs

Eu3+-activated La2W3O12 phosphors have been synthesized by using the traditional solid-state reaction. X-ray diffraction, photoluminescence (PL) spectra at room temperature and high temperature, and luminescence decay kinetics have been used to characterize the synthesized samples. For the PL emission spectra, the electric dipole transition 5D0-7F2 of Eu3+ is the dominant one. The chromaticity coordinate is (0.665, 0.334), which is close to the National Television Standard Committee standard value for red phosphor (x = 0.67, y = 0.33). For the excitation spectrum, the La2W3O12:Eu3+ phosphor shows an intense absorption near 400 nm, which is available for near-UV-excited white LEDs. An analysis based on the Inokuti-Hirayama model shows that the interaction between Eu3+ ions occurs via a dipole-quadrupole type interaction.