Pr3+-Activated LiTaO3 Crystal for a Dual-Mode and Dual-Channel Versatile Luminescence Thermometer

To cater to the requirements of integrated temperature sensing for diverse applications in optoelectronics and biomedicine, a dual-mode and dual-channel versatile thermometry strategy was proposed by utilizing Pr³⁺-activated luminescence. Stemming from population reallocation via the intervalence charge transfer state, different thermal responds of two sets of emissions originating from ³P₀ and ¹D₂ were observed in the important photoelectric material LiTaO₃. The fluorescence intensity ratio modes R₆₁₆/₅₁₀ and R₇₁₃/₇₆₄ offered visible and near-infrared spectral channels, respectively, for various sensing scenarios. The relatively sensitivities (S_R) were further improved with maximum values of 0.70 %K^–1 and 0.41%K^–1, respectively, via optimizing the choice of integrated spectral ranges. Moreover, the complementary lifetime mode excelled at higher temperatures with a maximum S_R of 0.42% K^–1. Therefore, Pr³⁺-activated LiTaO₃ enabled high-performance thermometry in wide temperature and spectral ranges, providing the future possibility of its integration within a variety of optoelectronic and biomedical devices.