Indium-induced changes in GaN(0001) surface morphology

First-principles calculations of the energetics of the In-terminated GaN(0001), (000 (1) under bar), (10 (1) under bar 1), and (10 (1) under bar (1) under bar) surfaces indicate that In has a substantial effect on the relative energies of formation of these surfaces. Indium-induced changes in the surface energetics enable the formation of inverted hexagonal pyramid defects having (10 (1) under bar 1) facets at the termination of threading defects on the (0001) surface of pseudomorphic InxGa1-xN films. For dislocations terminating on the InxGa1-xN(000 (1) under bar) surface, the calculations predict that large ( 10 (1) under bar (1) under bar) faceted defects are not energetically favorable.