Phosphorescence and thermoluminescence of uv-irradiated CaO powders at temperatures from 120 to 350 K

Long-lived phosphorescence and thermoluminescence (TL) from uv-irradiated CaO powders under high vacuum are observed at low temperatures. The emission spectra of phosphorescence and TL have a peak at about 3.0 eV. On the basis of the phosphorescence decay curves, TL glow curves, and ESR data, a plausible emission mechanism is discussed in terms of thermally assisted tunneling recombination between electron traps near the surfaces and hole traps.