High temperature sensitivity phosphor based on an old material: Red emitting H3BO3 flux assisted CaTiO3: Pr3

High temperature sensitivity phosphor based on an old material red emitting CaTiO3: Pr3+ phosphor prepared via H3BO3 flux assisted solid-state reaction is reported. The typical sample possesses the orthorhombic perovskite phase and no impurity is found. The optical bandgap value is ~3.59 eV. There exists a single red emission with ideal color purity. The average long-afterglow decay time is 87.7s, the average trap depth is 0.76 eV. The maximum absolute sensitivity at 473 K is equal to ~0.0258 K-1 and the maximum relative sensitivity is estimated to be 7.69% K−1 at 298 K with the resolution of 0.26–0.65 K, indicating the suitability of the material for temperature sensitivity application. A possible mechanism for the quenching of 3Pj emission at room temperature and the thermal quenching process of 1D2 level through intervalence charge transfer state are proposed from the configurational coordinate diagram. [Display omitted] •High temperature sensitivity phosphor based on H3BO3 flux assisted CaTiO3: Pr3+.•The CIE chromaticity coordinates are very close to that of the ideal red light.•IVCT state interfered thermometers with maximal Sa and Sr is ~~0.0258 K-1 and~ 7.69% K−1.•Ranking among the highest ones for inorganic optical thermometric materials reported before.•Providing a promising pathway to develop high optical temperature sensitivity.