Single-phase Ce3+-Mn2+-Tb3+ tri-codoped barium-yttrium-silicate phosphors

Ce3+-Mn2+-Tb3+ cooperative barium-yttrium-orthosilicate phosphors composed of Ba9-3m/2-n-3p/2CemMnnTbpY2Si6O24 (m = 0.005-0.4, n = 0-0.5, p = 0-0.5) were prepared using a solid-state reaction. The X-ray diffraction patterns of the resultant phosphors were examined to index the peak positions. The photoluminescence (PL) excitation and emission spectra of the Ce3+-Mn2+-Tb3+ activated phosphors were clearly monitored. The dependence of the luminescent intensity of the Mn2+-Tb3+ co-doped Ba9-3m/2CemY2Si6O24 host lattices on Ce3+ content (m = 0.025, 0.1) was also investigated. Co-doping Mn2+ into the Ce3+-Tb3+ co-doped host structure enabled energy transfer from Ce3+ to Mn2+; this energy transfer mechanism is discussed. The phosphors of Ce3+-Mn2+-Tb3+ doped Ba9Y2Si6O24 host lattice were prepared for efficient white-light emission under NUV excitation. With these phosphors, the desired CIE values including white region of the emission spectra were achieved.