Ground-state structure of oxidized diamond (100) surface: An electronically nearly surface-free reconstruction

A candidate ground state of the technologically important oxidized diamond (100) surface is identified via theoretical calculations. Ab initio calculations indicate that the proposed methoxyacetone surface structure, containing both carbonyl and epoxide groups, is the most stable reconstruction at ambient and elevated temperatures. This finding is expected to solve the long-standing structural uncertainty regarding the oxidized diamond (100) surface. The prominence of this configuration gives rise to remarkable electronic properties: the highest occupied and lowest unoccupied surface states are lowered and raised, respectively, relative to that of a clean or hydrogenated surface. Therefore, surface electronic states have little effect on the bulk band gap, which makes it an electronically nearly surface-free reconstruction. This may have profound implications for the development of diamond-based nanoelectronics and efficient single-photon emitters for quantum information processing and sensing.