NIR Light-triggered Green Emitting Perovskite-based Phosphor for Optical Thermometry and Future Molecular Logic Gate Applications.

Er and Yb doped CaTiO phosphors were synthesized via the solution combustion method and analyzed for structural, morphological, and optical properties using X-ray powder diffraction, field emission scanning electron microscopy, and photoluminescence spectroscopy. The Er ions showed green and red emissions when excited by a 980 nm infrared source. Power-dependent emission spectra were used to study the up-conversion process, and a rate equation model was proposed for clarity. For temperature sensing, the phosphor's temperature-dependent emission lines were examined between 303 and 583 K. This analysis was conducted using the fluorescence intensity ratio method. Relative sensitivities of 1.14%, 1.66%, 0.15%, and 0.33% K were observed for various thermally and non-thermally linked transitions. The phosphor also demonstrated potential for molecular logic gate applications, achieving switching ratios of ~ 170.86% for the AND gate and ~ 72.28% for the INHIBIT gate when heat and IR excitation were used as inputs. This material shows promise for both optical thermometry and future molecular logic devices.