We present first-principle calculations of the structure and energetics of the GaN(101)
surface, and present models for the reconstructions. A strong preference for In surface segregation and occupation of specific surface sites is demonstrated. We argue that inverted pyramid defect formation is enhanced by segregation of In on (101)
facets. We propose that the chemical ordering recently observed in InGaN alloys is driven by the preference for In incorporation at the sites of reduced N coordination present at step edges during growth on the (0001) and (000)
surfaces. © 1999 American Institute of Physics.