Furthermore, it was also demonstrated that theGZT:Mn4+/Er3+ phosphors were promising luminescent materials for simultaneous UC and downshift emissions. In addition, Lee et al.reported that the Eu3+ ions doped GZT red phosphors were promisin luminescent materials used as UV-based white light-emitting diodes and field emission displays.36 Although many admirable results have been achieved in the Ln3+-doped GZT host, more efforts are stillneeded to further investigate the luminescent properties of GZT host.Herein, GZT:Yb3+/Er3+ phosphors were successfully fabricated by the sol-gel method.