A four-mode high-sensitive optical thermometer based on Ca3LiZnV3O12:Sm3+ phosphors

High-precision optical thermometer has been a tremendous magnet for interests of researchers due to the rapid advancement of technology. Herein, Ca3LiZnV3O12:Sm3+ phosphors with two luminescent centers were fabricated. Detailed investigations into their structure, luminescent properties, and energy transfer from VO43− to Sm3+ were carried out. With temperature increasing, the emission and excitation spectra of VO43− and Sm3+ perform different thermal responses, leading to obvious thermochromic behavior. Therefore, a four-mode luminescent thermometry relied on fluorescence intensity, fluorescence intensity ratio, Commission Internationale de L'Eclairage coordinates, and excitation intensity ratio is designed. Their maximal relative sensitivities (SR) can reach 2.41 %K−1 (342 K), 1.91 %K−1 (336 K), 0.567 %K−1 (303 K), and 1.27 %K−1 (303 K), respectively. More importantly, the SR values of fluorescence intensity , fluorescence intensity ratio , and excitation intensity ratio modes can be maintained above 1.19 %K−1, 0.92 %K−1, and 0.83 %K−1 between 303 and 543 K, which are superior to those of thermometers based on thermally coupled energy levels. The excellent thermometrical performance indicates that Ca3LiZnV3O12:Sm3+ might be candidate in temperature monitoring applications.