GaN and InGaN(112_2) surfaces: group-III adlayers and indium incorporation

First-principles calculations of total energy performed for clean and In-rich GaN(112_2) surfaces indicate that indium will, for the same chemical potential, incorporate in higher concentrations on the (112_2) surface than on the (101_0) surface. Because an In atom is larger than the Ga atom it replaces there is an effective repulsive interaction between incorporated In atoms on the surface. On the In-rich (112_2) surface the repulsive interaction is much weaker than it is on the (101_0) surface. For this reason the concentration of indium atoms incorporated in growth on the (112_2) surface can exceed the concentration obtained on the (101_0) surface.

Citation

Northrup, J. E. GaN and InGaN(112_2) surfaces: group-III adlayers and indium incorporation. Applied Physics Letters. 2009 September 28; 95 (13): 133107.