Luminescence of [Be](+) centre in MgO : Be

摘要

Doping of MgO single crystals with Be results in the formation of numerous Be-containing paramagnetic centres, easily detectable by EPR, and creates an intensive luminescence band at 6.2 eV, observable at T < 200 K, and gives rise to new thermoluminescence peaks at 147 and 190 K. A paramagnetic centre with a rhombic symmetry that decays at 160 K was identified as a [Be](+) (i.e. O--Be2+) centre-a hole trapped by O2- lattice ion near a Be2+ perturbing defect. The luminescence excitation and isochronal annealing studies led to the conclusion that the 6.2 eV luminescence arises at the radiative decay of electron excitations near Be2+. These excitations can be created at the recombination of electrons with the holes localised in the [Be](+) centres, at the recombination of holes with the electrons trapped in the Be1+ centre or at a direct excitation of oxygen near the Be2+ ion. (C) 2003 Elsevier Ltd. All rights reserved.