Influence of thermal effect on upconversion luminescence of Y2(MoO4)3:Yb3+, Ln3+ (Ln = Er, Tm)

Upconversion luminescence of Yb3+/Er3+ and Yb3+/Tm3+ co-doped Y2(MoO4)3 phosphors under 980 nm excitation is investigated. It is demonstrated that Yb3+ co-doping causes a significant thermal effect. For Yb3+ and Er3+ co-doped case, the thermal effect, the long-distance energy migration and the energy transfer from Er3+ to Yb3+ are responsible for the abnormal luminescence quenching. In the case of Yb3+ and Tm3+ co-doped, the thermal effect improves the excited efficiency of Tm3+, and thus the luminescence of Tm3+ continues to strengthen at the Yb3+ concentration that causes Er3+ luminescence quenching. These results contribute to the design of the efficient upconversion materials.