Photoluminescence studies on Eu2+ and Ce3+-doped Li2SrSiO4

The luminescence of Li2SrSiO4: 0.01Eu, xCe (x=0.0025, 0.005, 0.0075, and 0.01) is studied as a potential ultraviolet light-emitting diode (UV-LED) phosphor that is capable of converting the ultraviolet emission of a UV-LED into white light with good luminosity. There are broad blue and yellow emissions peaked at 413 and 575 nm, respectively. The two emissions come from d-f transitions of Ce3+ and Eu2+, respectively. The emission intensity of Li2SrSiO4: 0.01Eu, xCe reaches its maximum at x=0.0075. The energy transfer from Ce3+ to Eu2+ is demonstrated to be the type of electric dipole-dipole interaction with considerable spectral overlap and nonradiative transition is calculated to dominate. The Commission International de I'Eclairage (CIE) chromaticity coordinates of Ce3+/Eu2+ substituted compounds is also discussed.