Largely enhanced luminescence intensity and improved optical temperature sensing properties in CaWO(4)–La(2)(WO(4))(3): Er(3+), Yb(3+) via regulating cations composition

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 Ca(2+) and La(3+) in CaWO(4)–La(2)(WO(4))(3), respectively. The up-conversion luminescence (UCL) and optical temperature sensing performance of rare earth ions Er(3+)/Yb(3+) co-doped CaWO(4)–La(2)(WO(4))(3) were studied. As guided by regulating cation composition through partial substituting Ca(2+) ions by La(3+) 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 0.2La(2)(WO(4))(3)–0.8CaWO(4): 1%Er(3+), 5%Yb(3+) is as 33.5 times as that of CaWO(4): 1%Er(3+), 5%Yb(3+) 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 0.2La(2)(WO(4))(3)–0.8CaWO(4): 1%Er(3+), 5%Yb(3+). 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.