LAUSR

A TeO2–Nb2O5–LiO2–CaO (TNLC) lithium–niobium–tellurite glass single-doped and co-doped with Tb3+, Sm3+, and Yb3+ ions was synthesized via a conventional melt-quenching method. The Tb3+–Sm3+ co-doped TNLC glass could be tuned to emit white light effectively by controlling the ratio of Tb3+ and Sm3+ in the glass. The fluorescence lifetime of the Tb3+–Sm3+ co-doped TNLC glass indicated the existence of multiple energy transfer channels, including from Tb3+ to Sm3+ ions and the reverse energy transfer from Sm3+ to Tb3+ ions. Taking advantage of these energy transfer channels, the color coordinates of the material could be changed from yellowish-pink and yellowish-green emissions to white emission by controlling the ratio of ions doped in TNLC glasses. The optimal molar concentration ratio between Tb3+ and Sm3+ ions for the best white light emission was 0.83 for the TNLC-0.5Tb0.6Sm sample. Changing the ratio of these rare-earth (RE) ions allowed tuning the color temperature of the material from 5616 to 7699 K. Thus, Tb3+–Sm3+ co-doped and Tb3+–Sm3+–Yb3+ tri-doped TNLC glasses are promising materials for color display applications and white light-emitting diodes (WLEDs).