Afterglow and Thermoluminescence of UV-Irradiated MgO Surfaces at Low Temperature

Abstract
Afterglow emission and thermoluminescence are observed on UV-irradiated MgO powders at low temperatures of 140 K-300 K under high vacuum. The main peak of the TL spectrum is at 3.1 eV with a shoulder at about 2.3 eV. A plausible emission process is discussed in terms of the tunneling recombination of an electron of Fs + centers and a hole of Vs - centers on the surfaces. The luminescence is quenched by O2 gas exposure at low temperature.