LARGE BAND-GAP BOWING OF INXGA1-XN ALLOYS

Band gap measurements have been performed on strained InxGa1-xN epilay ers with x less than or equal to 0.12. The experimental data indicate that the bowing of the band gap is much larger than commonly assumed. We have performed first-principles calculations for the band gap as a function of alloy composition and find that the bowing is strongly com position dependent. lit x=0.125 the calculated bowing parameter is b=3 .5 eV, in good agreement with the experimental values. (C) 1998 Americ an Institute of Physics.