Sm²⁺ doped strontium pentaborate chloride for dual-modal temperature imaging

A multimodal thermometry material, Sm²⁺ doped Sr₂B₅O₉Cl, was successfully synthesized and investigated for its potential in thermometry and temperature imaging. The temperature-dependent behaviors of the fluorescence intensity ratio (FIR), decay lifetime, dual-light-path intensity ratio (DLIR) and time-resolved intensity ratio (TRIR) were systematically studied, revealing high temperature sensitivity for each strategy. To facilitate temperature imaging, charge-coupled device (CCD) cameras were employed instead of conventional spectrometers to record the spatial distribution of fluorescence intensity and establish calibration curves correlating temperature. Temperature distribution imaging on printed circuit boards was successfully demonstrated using both the DLIR method and the TRIR technique. The results indicate that the developed material exhibits excellent performance for both thermometric sensing and temperature imaging applications.