Photodiode-Based TL Reader for Analysing Persistent Luminescent Phosphor (March 2025)

Persistent luminescent phosphors (PLPs) are being studied due to their high intensity and prolonged emission after the removal of the excitation source. The study of this phosphor has been performed using a thermoluminescence (TL) reader based on a photomultiplier tube (PMT). However, a TL reader based on PMT suffers from two flaws, i.e., PMT saturation at high-intensity light emitted by the persistent phosphor and the decrease in glow peak height with the increase in heating rate (commonly referred to as heating rate-induced thermal quenching). A new TL reader was constructed to overcome these flaws observed in the case of persistent phosphor, and a comparative study of this reader was performed with the commercially available TL reader from Nucleonix. It was found from the comparative analysis that the photodiode is best suited for the study of persistent phosphors, and its result was in accord with the theoretically predicted pattern. Also, the theoretically predicted pattern, i.e., an increase in glow peak height with the increase in heating rate, may be used as a benchmark to test the reliability of the TL reader.