Model for the deep defect-related emission bands between 1.4 and 2.4 eV in AlN

We report on defect-related photoluminescence bands in the range from 1.4 to 2.4 eV in aluminum nitride bulk crystals and layers. Using continuous photoluminescence, photoluminescence excitation, and time-resolved photoluminescence spectroscopy, we assign these bands to donor-acceptor pair transitions between shallow donor states or related slightly deeper DX- states of silicon or oxygen donors, and three different types of deep acceptors. These three different acceptors are most likely a (V-Al - 2(O-N)) complex, a (V-Al - O-N) complex, and an aluminum vacancy V-Al, or different charge states of these. (C) 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim