The fluorescence self-healing mechanism and temperature-sensitive properties of a multifunctional phosphosilicate phosphor

The temperature-dependent fluorescence characteristic is a key index of rare-earth ion-doped functional materials. In this paper, the structure, photoluminescence property, trap distribution and self-healing mechanism are studied in detail by XRD, photoluminescence spectra, decay times, the temperature-dependent fluorescence characteristic and cathodoluminescence spectrum. We developed a multicationic site phosphosilicate phosphor Ca8Al2(PO4)6(SiO4): Ce3+, Mn2+ to obtain the luminous self-healing property. In this work, we tried to change the energy and density distributions of traps by designing and adjusting synthesis scheme of target material and finally realized self-suppression of emission declined by energy compensation from traps or energy transfer between Ce3+ and Mn2+. As we expected, photoluminescence intensity of Ce3+ and Mn2+ at 250 °C is 40% and 300%, respectively, of their initial intensity at ambient temperature for co-doped representative sample, and it indicates that the emission degeneration of Mn2+ is obviously suppressed with the increase in temperature. A highly thermally sensitive fluorescence intensity ratio is obtained in a broad temperature range, and it implies that this material could be applied to a temperature sensing sensor. The fitting and calculated results show a good signal discriminability with the maximum absolute sensitivity 0.0097 K−1 and maximum relative sensitivity 2.1% K−1, respectively.