Enhancement and Stabilization of Hole Concentration of Hydrogen-Terminated Diamond Surface Using Ozone Adsorbates

The p-type conductivity of H-terminated diamond surface can be linked to adsorption of a specific gas species on the surface. O3, NO2, NO, and SO2 were identified as adsorbates, which induce holes on the H-terminated diamond surface. Among them, exposure to O3 increases hole concentration the most. The O3-increased concentration remains high even after exposure to the gas has stopped, indicating that ozone is the most stable adsorbent. X-ray photospectroscopy spectra of O3-adsorbed H-terminated diamond surface show partial oxidation of the surface and upward band bending and are very similar to those of NO2 exposed diamond surfaces.