Strong red upconversion luminescence of Yb3+/Er3+ co-doped Sc6WO12 phosphor for optical thermometry

Herein, a strong red upconversion phosphor of Yb 3+ /Er 3+ co-doped Sc 6 WO 12 was prepared by employing an equivalent substitution approach. When irradiated by 980 nm near-infrared laser, the phosphor emits strong 660 nm red light. The main excitation mechanism for its red upconversion luminescence emission is the energy transfer process, through which the Er 3+ ions is promoted from the 4 I 13/2 energy level to the 4 F 9/2 energy level. In addition, it is noteworthy that the multimode upconversion luminescence phosphor exhibits three different trends upon temperature change, and its upconversion emission integral intensity ratio exhibits a linear relationship with temperature in the range of 298 K–623 K. This special property makes the phosphor promising for applications in optical temperature measurement.