Abstract
This paper gives the composition dependence of the bandgap energy for highly doped n-type Al
x
Ga
1−
x
N. We report results of the bowing parameter obtained using a random simulation. Three groups of Al
x
Ga
1−
x
N semiconductors were considered and which are distinguishable by their non degenerate or degenerate character in the doping density (10
17⩽
N
D⩽10
20
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 Al
x
Ga
1−
x
N alloys.