Light-induced inter-electron-trap charge movement in annealed Al2O3:C,Mg

Inter-electron-trap charge movement induced under phototransferred thermoluminescence (PTTL) in Al2O3:C,Mg annealed at 700 and 900 °C is reported. Such annealing modifies the emission spectrum and electron trapping states in Al2O3:C,Mg. The glow curve of Al2O3:C,Mg annealed at 700 °C has eight peaks at 46, 76, 100, 170, 199, 290, 330 and 375 °C respectively. In comparison, that of the sample annealed at 900 °C has nine at 49, 80, 100, 174, 206, 235, 290, 335 and 375 °C. The peaks are labelled I, II, III … in that order. Only peaks I-IV re-appear under phototransfer. The PTTL is analysed qualitatively as well as by computational and phenomenological models as systems of an acceptor and multiple donors. Point defects that likely contribute to emergence of PTTL are discussed and are deduced to lie mostly in the oxygen sub-lattice.