Highly sensitive Tm3+/Yb3+ codoped SrWO4 for optical thermometry

In this paper, Tm3+/Yb3+ codoped SrWO4 materials for optical thermometry is synthetized and characterized. Under a 980nm diode laser excitation, the upconversion emission spectra of the material under different temperature were measured in the temperature range of 308 K-573 K. The fluorescence intensity ratios (FIRS) of the Tm3+:F-3(2) -> H-3(6) (684nm) and TM3+:F-3(3) -> H-3(6) (696nm) emissions to the Tm3+:H-3(4) -> H-3(6) (814nm) emission were respectively calculated. The results show that the natural logarithm of both FIRs change linearly with the reciprocal of temperature. The maximum absolute sensitivities are 0.00544 K-1 and 0.00617 K-1 at 323 K, respectively, which are about one order higher than that of most of the previously reported Tm3+/Yb3+ doped materials with other hosts. The results indicate that SrWO4:Tm3+/Yb3+ is a very promising material for highly sensitive optical thermometry. (C) 2018 Elsevier B.V. All rights reserved.