Luminescent properties of the oxygen impurity centres in A1N

Emission luminescence spectra of A1N with oxygen impurity are composed of several overlapping bands ranging from 2.37 eV to 3.51 eV. The intensity of these bands depends on the excitation conditions. The Stokes shift of corresponding excitation bands is ～0.93 eV; this shift is compatible with the experimental half-width of individual bandsΘ ～ 0.46 eV. The observed complex spectra are ascribed to the excitation and recombination processes in D-A complexes formed of substitutional oxygen donors O_N and aluminum vacancies V _Al . Tentative models of these centers are proposed.