Energy gaps and bowing parameters of InAlGaN ternary and quaternary alloys

We report a study of band gap energies and bowing parameters of all possible families of ternary and quaternary nitride alloys. The experimental band gap energies (E g) measured by photoluminescence, optical transmission and reflection methods, were strain‐corrected in order to obtain for every sample the unstrained value of its E g. For Alx Ga1–x N the bowing parameter is equal to 1 eV, but the alloys Inx Ga1–x N and Inx Al1–x N exhibited strong dependence of the bowing parameter on alloy composition. Finally, we investigated many quaternaries alloys Inx Aly Ga1–x –y N and we observed that the bowing parameter appears also to be very sensitive on In content. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)