First-principles study of wurtzite InN (0001) and (000(1)over-bar) surfaces

Density-functional calculations are used to study various plausible structures of the wurtzite InN (0001) and (000 (1) over bar) surfaces. These structures include the unreconstructed surfaces, surfaces with monolayers of In or N, several possible coverages and locations of In or N adatoms and vacancies. The stable structure of the (0001) surface under N-rich conditions is the unreconstructed, In-terminated, surface, while under In-rich conditions the stable surface has a 3/4 monolayer of In atoms. The stable structure of the InN (000 (1) over bar) surface corresponds to a full monolayer of In atoms in the atop sites (directly above the N atoms) over the entire range of accessible In (or N) chemical potential. The atomic structures of the low-energy structures are also discussed.