Enhanced upconversion emission in Er3+: BaWO4 through Gd3+ incorporation and optical thermometry

In this paper, a series of Er3+/Gd3+ co-doped BaWO4 phosphors have been synthesized through solid state reaction method. The corresponding upconversion(UC) luminescence properties were investigated under 980 nm excitation. The UC emission intensities of Er3+ ions were enhanced with Gd3+ doped, which was interpreted by crystal field deformation. Based on the fluorescence intensity ratio (FIR) technique, the temperature sensing characteristics of Er3 + ions were investigated. The maximum absolute sensitivity reached 15.49 × 10−3 K−1 at 523 K. The above results indicated that the Er3+/Gd3+ co-doped BaWO4 phosphor was a high efficient UC luminescence material and it could be used as photonic devices, temperature sensor purposes and an optical heater.