Abstract The electronic properties of hydrogen- and oxygen-terminated diamond surfaces exposed to the air are investigated by scanning probe microscopy (SPM). The results indicate that for the hydrogen-terminated diamond surface a shallow acceptor above the valence-band-maximum (VBM) appears in the band gap. However, the oxygen-terminated diamond film exhibits a high resistivity with a wide band gap. Based on the density-functional-theory, the densities of states, corresponding to molecular adsorbate in hydrogenated and oxygenated diamond (100) surfaces, are studied. The results show that the shallow acceptor in the band gap for the hydrogen-terminated diamond film can be attributed to the interaction between the surface C--H bonding orbitals and the adsorbate molecules, while for the oxygen-terminated diamond film, the interaction between the surface C--O bonding orbitals and the adsorbate molecules can induce occupied states in the valence-band.
Received: 17 October 2008
Revised: 30 November 2008
Accepted manuscript online:
PACS:
73.20.Hb
(Impurity and defect levels; energy states of adsorbed species)
(Microscopy of surfaces, interfaces, and thin films)
Fund: Project supported by the National
Natural Science Foundation of China (Grant No 50675112), National
Basic Research Program of China (Grant No 2007CB707702), and the
China Postdoctoral Science Foundation (Grant No 20070410515).
Cite this article:
Liu Feng-Bin(刘峰斌), Wang Jia-Dao(汪家道), Chen Da-Rong(陈大融), and Yan Da-Yun(颜大运) Electronic properties of hydrogen- and oxygen-terminated diamond surfaces exposed to the air 2009 Chin. Phys. B 18 2041
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