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Electronic properties of hydrogen- and oxygen-terminateddiamond surfaces exposed to the air
Liu Feng-Bin,Wang Jia-Dao,Chen Da-Rong,Yan Da-Yun,
中国物理 B , 2009,
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.
Reconstructions of diamond (100) and (111) surfaces: Accuracy of the Brenner potential  [PDF]
A. V. Petukhov,A. Fasolino
Physics , 2000, DOI: 10.1002/1521-396X(200009)181:1<109::AID-PSSA109>3.0.CO;2-W
Abstract: We present a detailed comparison of the structural predictions of the effective many-body Brenner potential with those of ab-initio studies for known reconstructions of diamond (100) and (111) surfaces. These results suggest high reliability of the Brenner potential for dealing with carbon-based structures where different types of bonding are present at the same time.
Structural and electronic properties of the SiC (100) surfaces
Soares, J. S.;Alves, H. W. Leite;
Brazilian Journal of Physics , 2006, DOI: 10.1590/S0103-97332006000300017
Abstract: in this work, we present our preliminary ab initio results for the structural and electronic properties of both si- and c-terminated sic (100) surfaces in (2×1) and c(2×2) reconstruction patterns. based on our results, we found that the si-terminated surfaces are dominated by weak bonded si-dimers, which are stabilized only at si-rich conditions, leading to (3×2) or more complex reconstruction patterns, as verified experimentally. also, our results show that the c-terminated surfaces is characterized by strong triply-bonded c-dimers, in a c(2×2) reconstruction pattern, which consists of c2 pairs over si bridge sites, in agreement with experimental results.
Electronic structures of hydrogenated and oxygenated boron-doped diamond films
氢、氧终端掺硼金刚石薄膜的电子结构
Liu Feng-Bin,Wang Jia-Dao,Chen Da-Rong,
刘峰斌,汪家道,陈大融
物理学报 , 2008,
Abstract: The hydrogenated and oxygenated boron-doped diamond films have been prepared by hydrogen-plasma treatment and boiling in the strong acids, respectively. By means of the X-ray photoelectron spectroscopy and contact angle measurements, the two surface-terminated diamond films have been evaluated. The scanning tunneling spectra have been measured by scanning probe microscope. The results indicated that for the hydrogenated diamond surface, the surface energy bands bend downwards and there exists a shallow acceptor above the valence band maximum. However, the surface energy bands for the oxygenated film bends upwards and its band gap is wide and clean. The conduction mechanisms for the two surface-terminated diamond films have been discussed.
Electronic structures of hydrogenated and oxygenated boron-doped diamond films
氢、氧终端掺硼金刚石薄膜的电子结构
Liu Feng-Bin,Wang Jia-Dao,Chen Da-Rong,
刘峰斌,汪家道,陈大融
中国物理 B , 2008,
Abstract: The hydrogenated and oxygenated boron-doped diamond films have been prepared by hydrogen-plasma treatment and boiling in the strong acids, respectively. By means of the X-ray photoelectron spectroscopy and contact angle measurements, the two surface-terminated diamond films have been evaluated. The scanning tunneling spectra have been measured by scanning probe microscope. The results indicated that for the hydrogenated diamond surface, the surface energy bands bend downwards and there exists a shallow acceptor above the valence band maximum. However, the surface energy bands for the oxygenated film bends upwards and its band gap is wide and clean. The conduction mechanisms for the two surface-terminated diamond films have been discussed.
Theoretical study of hydrogen-covered diamond (100) surfaces: A chemical potential analysis  [PDF]
Suklyun Hong,M. Y. Chou
Physics , 1996, DOI: 10.1103/PhysRevB.55.9975
Abstract: The bare and hydrogen-covered diamond (100) surfaces were investigated through pseudopotential density-functional calculations within the local-density approximation. Different coverages, ranging from one to two, were considered. These corresponded to different structures including 1x1, 2x1, and 3x1, and different hydrogen-carbon arrangements including monohydride, dihydride, and configurations in between. The formation energy of each phase was expressed as a function of hydrogen chemical potential. As the chemical potential increased, the stable phase successively changed from bare 2x1 to (2x1):H, to (3x1):1.33H, and finally to the canted (1x1):2H. Setting the chemical potential at the energy per hydrogen in H$_2$ and in a free atom gave the (3x1):1.33H and the canted (1x1):2H phase as the most stable one, respectively. However, after comparing with the formation energy of CH$_4$, only the (2x1):H and (3x1):1.33H phases were stable against spontaneous formation of CH$_4$. The former existed over a chemical potential range ten times larger than the latter, which may explain why the latter, despite of having a low energy, has not been observed so far. Finally, the vibrational energies of the C-H stretch mode were calculated for the (2x1):H phase.
A Study of the affect of N and B doping on the growth of CVD diamond (100):H 2 X 1 surfaces  [PDF]
M. Kaukonen,R. M. Nieminen,P. K. Sitch,G. Jungnickel,D. Porezag,Th. Frauenheim
Physics , 1997, DOI: 10.1103/PhysRevB.57.9965
Abstract: We present a study of the effects of Nitrogen and Boron doping on the growth of CVD diamond in the (100) mechanism. These are the first calculations of this type and show that, in accordance with recent experimental results, the presently accepted growth mechanism, that due to Harris, is cataylsed by the presence of subsurface Boron impurities. In contrast, we find that the Harris Mechanism cannot explain growth in the presence of subsurface N and suggest an alternative mechanism.
Electronic properties of isolated nickel in diamond
Larico, R.;Justo, J. F.;Machado, W. V. M.;Assali, L. V. C.;
Brazilian Journal of Physics , 2004, DOI: 10.1590/S0103-97332004000400038
Abstract: isolated nickel impurities in diamond have been investigated using the spin-polarized full-potential linearized augmented plane wave total energy method. the electronic and atomic structures, symmetries, transition energies, and formation energies of substitutional and interstitial ni impurities in diamond were computed. the results were discussed in the context of the electrically active centers in synthetic diamond.
Work function measurements of vanadium doped diamond-like carbon films by ultraviolet photoelectron spectroscopy  [PDF]
Akihiko Shigemoto,Tomoko Amano,Ryozo Yamamoto
Physics , 2014,
Abstract: Vanadium doped diamond-like carbon films prepared by unbalanced magnetron sputtering have been investigated by X-ray and ultraviolet photoelectron spectroscopy measurements for the purpose of revealing electronic structures including values of work function on the surfaces. In addition to these photoelectron measurements, X-ray diffraction measurements have been performed to characterize the crystal structures.
Spatially-resolved electronic and vibronic properties of single diamondoid molecules  [PDF]
Yayu Wang,Emmanouil Kioupakis,Xinghua Lu,Daniel Wegner,Ryan Yamachika,Jeremy E. Dahl,Robert M. K. Carlson,Steven G. Louie,Michael F. Crommie
Physics , 2007, DOI: 10.1038/nmat2066
Abstract: Diamondoids are a unique form of carbon nanostructure best described as hydrogen-terminated diamond molecules. Their diamond-cage structures and tetrahedral sp3 hybrid bonding create new possibilities for tuning electronic band gaps, optical properties, thermal transport, and mechanical strength at the nanoscale. The recently-discovered higher diamondoids (each containing more than three diamond cells) have thus generated much excitement in regards to their potential versatility as nanoscale devices. Despite this excitement, however, very little is known about the properties of isolated diamondoids on metal surfaces, a very relevant system for molecular electronics. Here we report the first molecular scale study of individual tetramantane diamondoids on Au(111) using scanning tunneling microscopy and spectroscopy. We find that both the diamondoid electronic structure and electron-vibrational coupling exhibit unique spatial distributions characterized by pronounced line nodes across the molecular surfaces. Ab-initio pseudopotential density functional calculations reveal that the observed dominant electronic and vibronic properties of diamondoids are determined by surface hydrogen terminations, a feature having important implications for designing diamondoid-based molecular devices.
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