Hybrid functional study of Si and O donors in wurtzite AlN

The properties of Si and O donors in wurtzite AlN have been studied by means of hybrid functional calculations, finding that both impurities form DX centres. In the case of Si, the stable DX centre is close in energy to the substitutional donor state and to a second metastable DX centre, thus explaining both the persistent effects and the broad range of activation energies observed experimentally. Ionisation energies have been computed for both Si and O donor states.