GaN and InGaN(1122) surfaces: Group-III adlayers and indium incorporation

First-principles calculations for clean and In-rich GaN(112̱2) surfaces indicate that indium will, for the same indium chemical potential, incorporate in higher concentrations on the (112̱2) surface than on the (101̱0) surface. Because In atoms are larger than Ga atoms, there is a strain-induced repulsive interaction between incorporated In atoms on the surface. This interaction is weaker on the (112̱2) surface in comparison to the (101̱0) surface.