Impact of hydrogen on indium incorporation at m-plane and c-plane In(0.25)Ga(0.75)N surfaces: first-principles calculations

Abstract

We present first-principles calculations for m-plane and c-plane In(sub_0.25)Ga(sub_0.75)N surfaces. The results elucidate the dependence of indium incorporation on growth conditions. For both surfaces the calculations indicate that In incorporation is energetically favorable provided the surface is wetted by In adlayers rather than passivated by hydrogen and NH2 groups. Growth of an In(sub_0.25)Ga(sub_0.75)N alloy therefore requires that the chemical potential of hydrogen be kept low. The results predict that a reduction in the abundance of hydrogen can lead to greater In incorporation on the m plane as well as the c plane.