Luminescence intensity ratio thermometry based on combined ground and excited states absorptions of Tb 3+ doped CaWO 4

Abstract

Luminescence intensity ratio (LIR) thermometry is of great interest, because of its wide applications of noninvasive temperature sensing. Here, a LIR thermometry based on combined ground and excited states absorptions is developed using CaWO 4 :Tb 3+ . The ratio of single luminescence ( 5 D 4 - 7 F 5 ) intensities under 379 and 413 nm excitations with opposite temperature dependences, attributed to the thermal coupling of ground state 7 F 6 and excited state 7 F 5 , is used to measure temperature. This LIR method achieves a high relative sensitivity of 2.8% K -1 , and can avoid complex spectral splitting by collecting all down-shifting luminescence bands, being a promising accurate luminescence thermometry.