New correlation between PTTL and POSL components in Al2O3:C

We describe newly found correlations between thermoluminescence (TL), pulsed optically stimulated luminescence (POSL), and phototransfer TL (PTTL) signals in Al2O3:C. A set of Al2O3:C samples were characterized for their TL and OSL curve shapes, as well as TL/POSL integrals and correlated with their PTTL behavior. POSL was used to separate the contribution from fast UV emission (F+ centers) and slow blue emission (F centers) OSL components in Al2O3:C. The results show that samples with high PTTL exhibit TL curve shapes with a peak at higher temperatures and OSL curves that decay slower compared to samples with low PTTL. The ratio of the integral POSL components, the UV/B ratio, was found to inversely correlate with the PTTL. We discuss the possible causes of our observations and outline the limitations of commonly used luminescence models to explain our data. These correlations add yet another piece to the puzzle of the stimulated luminescence mechanisms of Al2O3:C.