Adatoms and vacancies on the diamond(111) surface

Abstract

First-principles total-energy and band-structure calculations are performed for a series of 2 × 2 adatom structures and vacancies on the diamond(111) surface. The optimized geometries are related to band structures with narrow or vanishing gaps. In contrast to silicon and germanium, we find that adatoms and vacancies on the diamond surface are energetically less favourable than the relaxed unreconstructed surface.