Atomic-scale visualization and surface electronic structure of the hydrogenated diamond C(100)-(2x1):H surface -: art. no. 195416

The surface electronic structure of the hydrogenated diamond C(100)-(2 x 1):H surface was studied using scanning tunneling microscopy (STM), valence band and core-level photoemission, and near-edge x-ray-absorption fine structure. The hydrogenated diamond surface was prepared ex situ by hydrogen plasma treatment. The STM topographies of the hydrogenated diamond surface, recorded with an atomic resolution, indicated the atomically smooth diamond surface. The current-voltage (I-V) spectroscopy was used to study the transport of electrons injected from the STM tip into the diamond surface. It has been shown that the electron transport is determined not only by the surface states available but it depends crucially on the amount of subsurface hydrogen and the charge redistribution at the surface. Annealing of the diamond surface induces desorption of the subsurface hydrogen. That affects the electron transport as evidenced from the analysis of the I-V spectroscopy curves. A qualitative model for the electron transport, taking into account the specific electronic structure of the hydrogenated diamond surface, has been proposed.