Determination of the energy structure of recombination centers in heavily doped AlxGa1-xN:Si epitaxial layers with x > 0.5

The photoluminescence properties of the intensive defect-related emission in heavily doped AlxGal-xN:Si layers with x > 0.5 have been investigated by photoluminescence (PL) spectroscopy. The PL band in AlN was attributed to donor-acceptor (DA) transitions. At the lowest Al content, the impurity band merges with the conduction band and DA transitions are replaced by electron-acceptor transitions involving the same acceptor. The energy structure of recombination centers was obtained using the model of configuration coordinates for Al0.67Ga0.33N.