Insights into anti-thermal quenching of photoluminescence from SrCaGa4O8 based on defect state and application in temperature sensing

Herein, a self-activated phosphor SrCaGa4O8 with excellent thermal stability was synthesized by high temperature solid state reaction method. It exhibited the broad emission range from 300 to 600 nm under 220 nm excitation, which may be caused by the intrinsic defects of host. Specifically, with the temperature increasing, the photoluminescence (PL) color changed from bluish to yellow-green and the maximum of PL intensity at 550 nm was obtained when reaching 493 K. From thermoluminescence curves and high temperature spectra, it was found that the anti-thermal quenching phenomenon could be dependent on the self-compensation of the carriers. Accordingly, the results of temperature-dependent intensity ratio and sensitivity show that SrCaGa4O8 may have potential in the optical temperature sensing.