Effects of high doping on the bandgap bowing for AlxGa1−xN

This paper gives the composition dependence of the bandgap energy for highly doped n-type AlxGa1−xN. We report results of the bowing parameter obtained using a random simulation. Three groups of AlxGa1−xN semiconductors were considered and which are distinguishable by their non degenerate or degenerate character in the doping density (1017⩽ND⩽1020 cm−3). A striking feature is the large discrepancy of the bandgap bowing (−2.02⩽b⩽2.94 eV), as was demonstrated from our calculations. This suggests that high doping may be a possible cause able to induce the large range of bowing parameters reported for AlxGa1−xN alloys.