Largely enhanced luminescence intensity and improved optical temperature sensing properties in CaWO4–La2(WO4)3: Er3+, Yb3+ via regulating cations composition

Abstract

High temperature sensing sensitivity and luminescence intensity of phosphors are crucial factors for excellent optical temperature sensing performance. Based on material design, the pure phase and two-phase solid solutions were prepared by regulating the relative content of cations Ca2+ and La3+ in CaWO4–La2(WO4)3, respectively. The up-conversion luminescence (UCL) and optical temperature sensing performance of rare earth ions Er3+/Yb3+ co-doped CaWO4–La2(WO4)3 were studied. As guided by regulating cation composition through partial substituting Ca2+ ions by La3+ ions, the UCL intensity of two-phase solid solutions at 552 nm is much higher than that of pure phase material. The UCL intensity of 0.2La2(WO4)3–0.8CaWO4: 1%Er3+, 5%Yb3+ is as 33.5 times as that of CaWO4: 1%Er3+, 5%Yb3+ material. More importantly, the high temperature sensing sensitivity (0.01026 K−1) is achieved in a wider temperature range 83–683 K in optimal UCL material 0.2La2(WO4)3–0.8CaWO4: 1%Er3+, 5%Yb3+. It is suggested that material design theory can be used as a powerful tool to accelerate discovery of novel optical temperature sensing materials, with implications even for the design of other optoelectronic materials.