Photoluminescence properties and analysis of spectral structure of R _2(MoO_4)~3: Eu~(3+) (R = La; Gd) phosphors

摘要

The site-selective excitation and emission spectroscopy and luminescence decay (lifetime) have been investigated in the ~5D_0 → ~7F_0 region using a pulsed, tunable, and narrowband dye laser. We observed two crystallographic sites for Eu~(3+) in La _2(MoO_4)_3 and one crystallographic site for Eu~(3+) in Gd_2(MoO_4)_3. The stark energy levels for Eu~(3+) at different sites were assigned from site-selective emission spectra. The luminescent properties of the assynthesized samples were also investigated, which showed strong lines at 395nm in excitation spectra and intensive red emission, indicating that they could be used as red components for white LEDs.