Phototransferred thermoluminescence in alpha-Al2O3:C

As part of an effort to understand the mechanisms of light-induced effects in alpha-Al2O3:C the phototransferred thermoluminescence (PTTL) peaks at similar to 260 K and at similar to 450 K have been monitored as a function of the time of illumination, the temperature to which the sample is heated between irradiation and illumination, the wavelength of the illuminating light and the dose of irradiation. At the excitation powers and wavelengths used in this study, the PTTL signal is linearly proportional to illumination time in the range of 10 s to 3000 s. The most effective wavelengths are in the short wavelength visible to UV range. The PTTL signal is proportional to the applied dose in the dose range from 6 mGy to 40 Gy. In addition, the position of the 450 K PTTL peak is observed to depend upon the dose of irradiation and the preheat temperature. The phototransfer processes are complex and appear to involve both electrons and holes.