Tunable White Emitting in Ternary Ce/Tb/Sm Codoped CaO-B2O3-SiO2 Glasses

A series of luminescent glasses composed of CaO-B2O3-SiO2 codoped with samarium oxide (Sm2O3), cerium oxide (CeO2), and terbium oxide (Tb4O7) were prepared by melting at high temperature. The spectroscopic properties of the samples were investigated by photoluminescence (PL) measurements and CIE color coordinate. Blue, green, and reddish orange emission bands were observed in the PL spectra of Ce/Tb/Sm codoped glasses. The combination of these emission bands gave white light when the glasses were excited by near ultraviolet light. As the proportion of Tb4O7 was decreased, a gradual shift from green to white emission was observed in the PL spectra of the glasses. These rare earth ions-doped glasses are potential candidates for white light-emitting diodes.