Enhanced Up-Conversion Luminescence Intensity of Tb3+-Yb3+ Doped Glass Ceramics by Doping with Li+ Ions

Abstract

Tb 3+ -Yb 3+ doped transparent glass ceramics containing Y 2 Ti 2 O 7 crystalline phase were prepared by the melt crystallization method. Under the optimal heat treatment conditions (720°C/2 h), the average grain size in glass ceramics is about 278 nm, and the transmittance in the visible region can reach 78%. The up-conversion luminescence intensity of the glass ceramic is stronger than that of the precursor glass, and this enhancement was analyzed by Judd-Ofelt theory. Meanwhile, the introduction of Li + does not change the crystalline phase of glass ceramics. The emission intensity of the green light of the 8% Li + doped glass ceramics is significantly enhanced by about 4.48 times under 980 nm excitation. The XRD refinement results indicate that the enhanced luminescence intensity is related to the change of Y 2 Ti 2 O 7 crystal lattice caused by Li + doping. The relevant luminescence mechanism was discussed in detail. The results indicate that Li + doped transparent glass ceramics open new avenues for green UC applications.

Keywords: Glass ceramics, Y2Ti2O7, Li+ doped, Up-conversion luminescence