Three-mode optical thermometer based on Ca3LiMgV3O12:Sm3+ phosphors

A series of Ca3-xLiMgV3O12:xSm3+ (CLMV:Sm3+) phosphors were elaborated to provide new optical temperature sensing materials. Their structures, morphologies, and luminescent properties were comprehensively explored. The energy transfer from VO43− to Sm3+ was illustrated using luminescent spectra and luminescent decay curves. The different temperature dependent emission and excitation characters of VO43− group and 4f-4f transition of Sm3+ were used to design a three-mode optical temperature sensor. Temperature dependent fluorescence intensity ratio (FIR) value of I(Sm3+) and I(VO43−), Commission International de L'Eclairage (CIE) coordinate, and excitation intensity ratio (EIR) value of I383nm/I405nm in excitation spectra are the three sensing modes. The maximum value of absolute sensitivity (SA) and relative sensitivity (SR) in FIR mode are 9.11 %K−1 at 513 K and 1.99 %K−1 at 357 K, respectively. And SR is bigger than 1.21 %K−1 between 303 and 513 K, which is superior to that of thermometry based on Er3+ doped upconversion phosphors. The maximum SR in EIR mode is 1.39 %K−1 at 393 K. Our results indicate that CLMV:Sm3+ phosphors might have potential application as optical thermometry with self-reference character.