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- 1. phys. stat. sol. (b) 245, 1298-1314 (2008) , “EPR identification of intrinsic defects in SiC”, J. Isoya, T. Umeda, N. Mizuochi, N. T. Son, E. Janzen, T. OhshimaThe structure determination of intrinsic defects in 4H-SiC, 6H-SiC, and 3C-SiC by means of EPR is based on measuring the angular dependence of the 29Si/13C hyperfine (HF) satellite lines, from which spin densities, sp-hybrid ratio, and p-orbital direction can be determined over... (Read more)Si SiC diamond| EPR Theory electron-irradiation thermal-meas./anneal-exp.| +1 -1 0(neutral) 1.0eV~ 13C 29Si C1h C3v Carbon Csi D2d EI5/6 HEI1 HEI9/10 P6/7 Silicon T1 Td Tv2a V1/2/3 Vc Vsi antisite dangling-bond mono(=1) motional-effect n-type p-type pair(=2) quartet semi-insulating spin-relaxation triplet vacancy .inp files: SiC/Baranov/Baranov_g.inp SiC/EI5_C1h/5.inp SiC/EI5_C3v/5.inp SiC/EI6_RT/6.inp SiC/HEI10/HEI10a.inp SiC/HEI10/HEI10b.inp SiC/HEI1_C1h/1.inp SiC/HEI9/HEI9a.inp SiC/HEI9/HEI9b.inp SiC/SI5_C1h/4.inp SiC/Ky2/Ky2.inp SiC/Tv2a/Main.INP SiC/Vsi-_II_4H/Main.INP SiC/Vsi-_II_6H/Main.INP SiC/Vsi-_I_4H/Main.INP SiC/Vsi-_I_6H/Main.INP | last update: Takahide Umeda
- 2. Phys. Rev. B 75, 245202 (2007) , “Identification of positively charged carbon antisite-vacancy pairs in 4H-SiC”, T. Umeda, J. Ishoya, T. Ohshima, N. Morishita, H. Itoh, and A. GaliAn antisite-vacancy pair and a monovacancy are a set of fundamental stable and/or metastable defects in compound semiconductors. Theory predicted that carbon antisite-vacancy pairs would be much more stable in p-type SiC than silicon vacancies and that they would be a common defect. However,... (Read more)
- 3. Phys. Rev. B 75, 115127 (2007) , “Molecular microelectrostatic view on electronic states near pentacene grain boundaries”, Stijn Verlaak and Paul HeremansGrain boundaries are the most inevitable and pronounced structural defects in pentacene films. To study the effect of those structural defects on the electronic state distribution, the energy levels of a hole on molecules at and near the defect have been calculated using a submolecular... (Read more)
- 4. Phys. Rev. B 75, 075420 (2007) , “Ab initio study of hydrogen interaction with pure and nitrogen-doped carbon nanotubes”, Zhiyong Zhang and Kyeongjae ChoDetailed studies of mechanisms for hydrogen dissociative adsorption and diffusion on pure and nitrogen-doped (8, 0) carbon nanotubes are carried out using the first-principles density functional theory method. (1) For pure carbon nanotubes, we have identified the energetically most favorable... (Read more)
- 5. Phys. Rev. B 75, 073409 (2007) , “Why thermal H2 molecules adsorb on SiC(001)-c(4×2) and not on SiC(001)-(3×2) at room temperature”, Xiangyang Peng, Peter Krüger, and Johannes PollmannIn a recent experiment, Derycke et al. have made the exciting observation that H2 molecules readily adsorb dissociatively on the c(4×2) but not on the 3×2 surface of SiC(001) at room temperature. To unravel this spectacular reactivity difference, we have investigated a... (Read more)
- 6. Phys. Rev. B 75, 035322 (2007) , “Ab initio study of electronic and magnetic properties of the C-codoped Ga1−xMnxN (100) surface”, Q. Wang, Q. Sun, and P. JenaFirst principles calculations based on gradient corrected density functional theory have been carried out to study the magnetic coupling between Mn atoms in pure and carbon doped Ga1−xMnxN thin films. We show that the ground state of Mn-doped GaN (100) thin... (Read more)
- 7. Phys. Rev. Lett. 98, 075503 (2007) , “Pseudoclimb and Dislocation Dynamics in Superplastic Nanotubes”, Feng Ding, Kun Jiao, Mingqi Wu, and Boris I. YakobsonPlastic relaxation of carbon nanotubes under tension and at high temperature is described in terms of dislocation theory and with atomistic computer simulations. It is shown how the glide of pentagon-heptagon defects and a particular type of their pseudoclimb, with the atoms directly breaking out of... (Read more)
- 8. Appl. Phys. Lett. 89, 202904 (2006) , “Effects of O vacancies and C doping on dielectric properties of ZrO2: A first-principles study”, Gargi Dutta, K. P. S. S. Hembram, G. Mohan Rao, and Umesh V. WaghmareThe authors determine electronic properties, structural stability, and dielectric response of zirconia (ZrO2) with oxygen vacancies (O vacancies) and carbon doping (C doping) using first-principles density functional theory calculations based on pseudopotentials and a plane wave basis.... (Read more)
- 9. Phys. Rev. B 74, 245420 (2006) , “Energetics, structure, and long-range interaction of vacancy-type defects in carbon nanotubes: Atomistic simulations”, J. Kotakoski, A. V. Krasheninnikov,, and K. NordlundThe presence of vacancy clusters in carbon nanotubes has been assumed to explain the formation of carbon peapods and the difference between the experimentally measured and theoretical fracture strength of nanotubes. We use atomistic simulations at various levels of theory to study the... (Read more)
- 10. Phys. Rev. B 74, 165404 (2006) , “Density functional study of gold atoms and clusters on a graphite (0001) surface with defects”, Jaakko Akola and Hannu HäkkinenAdsorption of gold atoms and clusters (N=6) on a graphite (0001) surface with defects has been studied using density functional theory. In addition to perfect graphite (0001), three types of surface defects have been considered: a surface vacancy (hole), a pyridinelike defect comprising three... (Read more)
- 11. Phys. Rev. B 74, 153403 (2006) , “Doping and the unique role of vacancies in promoting the magnetic ground state in carbon nanotubes and C60 polymers”, Antonis N. Andriotis, R. Michael Sheetz, and Madhu MenonThe role of various types of defects in establishing the magnetic properties of the C60-based polymers and the single-wall carbon nanotubes is investigated. Comparing the role of carbon vacancies, and that of substitutional impurity atoms X (X=N, B, O, Si, P, and S) in... (Read more)
- 12. Phys. Rev. B 73, 161201(R) (2006) , “Thermally stable carbon-related centers in 6H-SiC: Photoluminescence spectra and microscopic models”, A. Mattausch, M. Bockstedte, O. Pankratov, J. W. Steeds, S. Furkert, J. M. Hayes, W. Sullivan, N. G. WrightRecent ab initio calculations [Mattausch et al., Phys. Rev. B 70, 235211 (2004)] of carbon clusters in SiC reveal a possible connection between the tricarbon antisite (C3)Si and the U photoluminescence center in 6H-SiC [Evans et al., Phys. Rev. B 66, 35204... (Read more)
- 13. Phys. Rev. B 73, 033204 (2006) , “Electrical characterization of metastable carbon clusters in SiC: A theoretical study”, A. Gali, N. T. Son, E. JanznFirst-principles calculations carried out in 3C- and 4H-SiC show that small metastable carbon clusters can be created in irradiated SiC. The metastable carbon clusters possess occupation levels in the p-type as well as in the n-type 4H-SiC. Depending on the... (Read more)
- 14. Phys. Rev. Lett. 96, 55501 (2006) , “Divacancy in 4H-SiC”, N. T. Son, P. Carlsson, J. ul Hassan, E. Janzén, T. Umeda, J. Isoya, A. Gali, M. Bockstedte, N. Morishita, T. Ohshima, H. ItohElectron paramagnetic resonance and ab initio supercell calculations suggest that the P6/P7 centers, which were previously assigned to the photoexcited triplet states of the carbon vacancy-antisite pairs in the double positive charge state, are related to the triplet ground... (Read more)
- 15. Phys. Rev. Lett. 96, 145501 (2006) , “Identification of the Carbon Antisite-Vacancy Pair in 4H-SiC”, T. Umeda, N. T. Son, J. Isoya, E. Janzn, T. Ohshima, N. Morishita, H. Itoh, A. Gali, M. BockstedteThe metastability of vacancies was theoretically predicted for several compound semiconductors alongside their transformation into the antisite-vacancy pair counterpart; however, no experiment to date has unambiguously confirmed the existence of antisite-vacancy pairs. Using electron paramagnetic resonance and first principles calculations we identify the SI5 center as the carbon antisite-vacancy pair in the negative charge state (CSiVC-) in 4H-SiC. We suggest that this defect is a strong carrier-compensating center in n-type or high-purity semi-insulating SiC. (Read more)SiC| ENDOR EPR Theory electron-irradiation optical-spectroscopy thermal-meas./anneal-exp.| -1 -2 1.0eV~ 13C 29Si C1h C3v Carbon Csi EI5/6 HEI1 HEI5/6 Nitrogen P6/7 SI5 Silicon Vc antisite bistable/metastable dangling-bond n-type pair(=2) semi-insulating vacancy .inp files: SiC/SI5_C1h SiC/SI5_80K SiC/SI5_100K | last update: Takashi Fukushima
- 16. Phys. Rev. B 71, 193204 (2005) , “Angular correlation of annihilation radiation associated with vacancy defects in electron-irradiated 6H-SiC”, A. Kawasuso, T. Chiba, T. HiguchiElectron-positron momentum distributions associated with vacancy defects in 6H-SiC after irradiation with 2-MeV electrons and annealing at 1000 °C have been studied using angular correlation of annihilation radiation measurements. It was confirmed that the above vacancy defects have... (Read more)
- 17. Phys. Rev. B 71, 193202 (2005) , “EPR and theoretical studies of negatively charged carbon vacancy in 4H-SiC”, T. Umeda, Y. Ishitsuka, J. Isoya, N. T. Son, E. Janzén, N. Morishita, T. Ohshima, H. Itoh, A. GaliCarbon vacancies (VC) are typical intrinsic defects in silicon carbides (SiC) and so far have been observed only in the form of positively charged states in p-type or semi-insulating SiC. Here, we present electron-paramagnetic-resonance (EPR) and photoinduced EPR (photo-EPR)... (Read more)
- 18. Phys. Rev. B 71, 125202 (2005) , “Positively charged carbon vacancy in three inequivalent lattice sites of 6H-SiC: Combined EPR and density functional theory study”, V. Ya. Bratus', T. T. Petrenko, S. M. Okulov, and T. L. PetrenkoThe Ky1, Ky2, and Ky3 centers are the dominant defects produced in the electron-irradiated p-type 6H-SiC crystals. The electron paramagnetic resonance study of these defects has been performed in the temperature range of 4.2300 K at... (Read more)
- 19. Phys. Rev. B 71, 035213 (2005) , “Possibility for the electrical activation of the carbon antisite by hydrogen in SiC”, A. Gali, P. Deák, N. T. Son, and E. JanzénCalculations predict the carbon antisite to be the most abundant intrinsic defect in silicon carbide in a wide range of doping. The isolated carbon antisite is, however, optically and electronically inactive, therefore, difficult to observe by usual experimental techniques. However, CSi... (Read more)
- 20. Phys. Rev. B 70, 245204 (2004) , “Silicon vacancy annealing and DI luminescence in 6H-SiC”, M. V. B. Pinheiro, E. Rauls, U. Gerstmann, S. Greulich-Weber, H. Overhof, and J.-M. SpaethCombining electron paramagnetic resonance measurements with ab initio calculations, we identify the VCCSi(SiCCSi) complex as a second annealing product of the silicon vacancy via an analysis of resolved carbon hyperfine interactions and of... (Read more)
- 21. Phys. Rev. B 70, 235212 (2004) , “EPR and theoretical studies of positively charged carbon vacancy in 4H-SiC”, T. Umeda, J. Isoya, N. Morishita, T. Ohshima, T. Kamiya, A. Gali, P. Deák, N. T. Son, E. JanzénThe carbon vacancy is a dominant defect in 4H-SiC, and the "EI5" electron-paramagnetic-resonance (EPR) spectrum originates from positively charged carbon vacancies (VC+) at quasicubic sites. The observed state for EI5, however, has been attributed to a... (Read more)
- 22. Phys. Rev. B 70, 235211 (2004) , “Structure and vibrational spectra of carbon clusters in SiC”, Alexander Mattausch, Michel Bockstedte, and Oleg PankratovThe electronic, structural, and vibrational properties of small carbon interstitial and antisite clusters are investigated by ab initio methods in 3C- and 4H-SiC. The defects possess sizable dissociation energies and may be formed via condensation of carbon interstitials, e.g.,... (Read more)
- 23. Phys. Rev. B 70, 205207 (2004) , “Hydrogen-related photoluminescent centers in SiC”, D. Prezzi, T. A. G. Eberlein, R. Jones, B. Hourahine, P. R. Briddon, S. ÖbergLocal density functional calculations are used to investigate models of the center responsible for a prominent set of luminescent lines with zero-phonon lines around 3.15 eV in hydrogen rich 4H-SiC and previously attributed to VSi-H. We find that the electronic structure of... (Read more)
- 24. Phys. Rev. B 70, 201204(R) (2004) , “Annealing of vacancy-related defects in semi-insulating SiC”, U. Gerstmann, E. Rauls, and H. OverhofThe annealing of P6/P7 centers (VCCSi pairs) in the presence of carbon vacancies in high concentrations typical for semi-insulating (SI) silicon carbide (SiC) is studied theoretically. The calculated hyperfine parameters support the suggestion of a negatively... (Read more)
- 25. Phys. Rev. B 70, 195344 (2004) , “Ab initio study of structural and electronic properties of planar defects in Si and SiC”, C. Raffy, J. Furthmüller, J.-M. Wagner, and F. BechstedtWe present ab initio calculations for internal interfaces in Si and SiC. Density-functional calculations within the local-density approximation and the pseudopotential-plane-wave approach are performed to understand the effect of such two-dimensional defects on the electronic properties. We... (Read more)
- 26. Phys. Rev. B 70, 115203 (2004) , “Different roles of carbon and silicon interstitials in the interstitial-mediated boron diffusion in SiC”, Michel Bockstedte, Alexander Mattausch, and Oleg PankratovThe interstitial and vacancy mediated boron diffusion in silicon carbide is investigated with an ab initio method. The boron interstitials in p-type and n-type materials are found to be far more mobile than the boron-vacancy complexes. A kick-out mechanism and an interstitialcy... (Read more)
- 27. Phys. Rev. B 70, 085202 (2004) , “Reassignment of phosphorus-related donors in SiC”, E. Rauls, M. V. B. Pinheiro, S. Greulich-Weber, and U. GerstmannCombining efficient density-functional based tight-binding molecular dynamics with ab initio calculations, we show that despite higher formation energies the incorporation of phosphorus at the carbon sublattice is favored by kinetic effects during the annealing processes. Based on the... (Read more)
- 28. Phys. Rev. B 69, 245205 (2004) , “Atomistic study of intrinsic defect migration in 3C-SiC”, Fei Gao, William J. Weber, M. Posselt, and V. BelkoAtomic-scale computer simulations, both molecular dynamics (MD) and the nudged-elastic band methods, have been applied to investigate long-range migration of point defects in cubic SiC (3C-SiC) over the temperature range from 0.36Tm to 0.95Tm (melting... (Read more)
- 29. Phys. Rev. B 69, 235202 (2004) , “Ab initio study of the annealing of vacancies and interstitials in cubic SiC: Vacancy-interstitial recombination and aggregation of carbon interstitials”, Michel Bockstedte, Alexander Mattausch, and Oleg PankratovThe annealing kinetics of mobile intrinsic defects in cubic SiC is investigated by an ab initio method based on density-functional theory. The interstitial-vacancy recombination, the diffusion of vacancies, and interstitials to defect sinks (e.g., surfaces or dislocations) as well as the... (Read more)
- 30. Phys. Rev. B 69, 125203 (2004) , “First-principles studies of the diffusion of B impurities and vacancies in SiC”, R. Rurali, E. Hernández, P. Godignon, J. Rebollo, and P. OrdejónIn this paper we analyze, by means of first-principles electronic structure calculations, the structural, energetic, and diffusive properties of B impurities in SiC as well as of vacancies. We focus our study on (i) determining the equilibrium structures of the impurity in the lattice by means of... (Read more)
- 31. Phys. Rev. B 69, 045322 (2004) , “Carbon antisite clusters in SiC: A possible pathway to the DII center”, Alexander Mattausch, Michel Bockstedte, and Oleg PankratovThe photoluminescence center DII is a persistent intrinsic defect which is common in all SiC polytypes. Its fingerprints are the characteristic phonon replicas in luminescence spectra. We perform ab initio calculations of vibrational spectra for various defect complexes and... (Read more)
- 32. Phys. Rev. B 68, 205201 (2003) , “Ab initio study of the migration of intrinsic defects in 3C-SiC”, Michel Bockstedte, Alexander Mattausch, and Oleg PankratovThe diffusion of intrinsic defects in 3C-SiC is studied using an ab initio method based on density functional theory. The vacancies are shown to migrate on their own sublattice. The carbon split-interstitials and the two relevant silicon interstitials, namely the tetrahedrally... (Read more)
- 33. Phys. Rev. B 68, 155208 (2003) , “Theoretical study of vacancy diffusion and vacancy-assisted clustering of antisites in SiC”, E. Rauls, Th. Frauenheim, A. Gali, P. DeákUsing the self-consistent-charge density-functional-based tight-binding (SCC-DFTB) method, we have investigated the migration of vacancies at high temperatures, taking into account the entropy contribution to the Gibbs free energy. We have found that the energy barrier for sublattice migration of... (Read more)
- 34. Phys. Rev. B 68, 125201 (2003) , “Aggregation of carbon interstitials in silicon carbide: A theoretical study”, A. Gali, P. Deák, P. Ordejón, N. T. Son, E. Janzén, and W. J. ChoykeAb initio supercell calculations have been carried out to investigate clusters of carbon interstitials in 3C- and 4H-SiC. Based on the calculated formation energies, the complex formation of carbon interstitials or their aggregation to carbon antisites is energetically favored... (Read more)
- 35. Phys. Rev. B 68, 085202 (2003) , “Physics and chemistry of hydrogen in the vacancies of semiconductors”, Bernadett Szûcs, Adam Gali, Zoltán Hajnal, Peter Deák, and Chris G. Van de WalleHydrogen is well known to cause electrical passivation of lattice vacancies in semiconductors. This effect follows from the chemical passivation of the dangling bonds. Recently it was found that H in the carbon vacancy of SiC forms a three-center bond with two silicon neighbors in the vacancy, and... (Read more)
- 36. Phys. Rev. B 67, 205202 (2003) , “Formation and annealing of nitrogen-related complexes in SiC”, U. Gerstmann, E. Rauls, Th. Frauenheim, and H. OverhofWe propose a mechanism for the annealing of vacancy-related defects in SiC, based on ab initio total energy calculations. Our mechanism is based on the formation and migration of carbon and nitrogen split interstitials resulting in CSi(NC)n or... (Read more)
- 37. Phys. Rev. B 67, 193102 (2003) , “Signature of intrinsic defects in SiC: Ab initio calculations of hyperfine tensors”, Michel Bockstedte, Matthias Heid, and Oleg PankratovTo reveal the microscopic origin of the spin-resonance centers in 3C- and 4H-SiC, we perform first-principles calculations of the hyperfine tensors for vacancy-related defects and interstitials. The calculations for the silicon vacancy corroborates the earlier experimental identification. The... (Read more)
- 38. Phys. Rev. B 67, 155203 (2003) , “Correlation between the antisite pair and the DI center in SiC”, A. Gali, P. Deák, E. Rauls, N. T. Son, I. G. Ivanov, F. H. C. Carlsson, E. Janzén, and W. J. ChoykeThe DI low temperature photoluminescence center is a well-known defect stable up to 1700 °C annealing in SiC, still its structure is not yet known. Combining experimental and theoretical studies, in this paper we will show that the properties of an antisite pair can reproduce... (Read more)
- 39. Phys. Rev. Lett. 91, 136101 (2003) , “Ab initio Simulations of Homoepitaxial SiC Growth”, M. C. Righi, C. A. Pignedoli, R. Di Felice, C. M. Bertoni, A. CatellaniWe present first-principle calculations on the initial stages of SiC homoepitaxial growth on the SiC(111)(×) surface. We show that the nonstoichiometric reconstruction plays a relevant role in favoring the attainment of high-quality films. The motivation is twofold: On one hand, we... (Read more)
- 40. Phys. Rev. Lett. 90, 225502 (2003) , “Z1/Z2 Defects in 4H–SiC”, T. A. G. Eberlein, R. Jones, P. R. BriddonFirst-principles calculations are carried out on models for the Z1/Z2 defects in 4HSiC which are found in as-grown and irradiated n-type material. We show that an interstitial-nitrogeninterstitial-carbon defect is exceptionally thermally stable,... (Read more)
- 41. Physica B 340-342, 15-24 (2003) , “Defects in SiC”, E. Janzén, I. G. Ivanov, N. T. Son, B. Magnusson, Z. Zolnai, A. Henry, J. P. Bergman, L. Storasta, F. CarlssonRecent results from studies of shallow donors, pseudodonors, and deep level defects in SiC are presented. The selection rules for transitions between the electronic levels of shallow donors in 4H–SiC in the dipole approximation are derived and the ionization energy for the N donor at... (Read more)
- 42. Phys. Rev. B 66, 024106 (2002) , “Cascade overlap and amorphization in 3C-SiC: Defect accumulation, topological features, and disordering”, F. Gao and W. J. WeberMolecular dynamics (MD) simulations with a modified Tersoff potential have been used to investigate cascade overlap, damage accumulation, and amorphization processes in 3C-SiC over dose levels comparable to experimental conditions. A large number of 10 keV displacement cascades were randomly... (Read more)
- 43. Phys. Rev. B 65, 184108 (2002) , “Alphabet luminescence lines in 4H-SiC”, T. A. G. Eberlein, C. J. Fall, R. Jones, P. R. Briddon, S. ÖbergFirst-principles density functional calculations are used to investigate antisite pairs in 4H-SiC. We show that they are likely to be formed in close proximity under ionizing conditions, and they possess a donor level and thermal stability consistent with the series of 40 photoluminescent lines... (Read more)
- 44. Phys. Rev. B 65, 085202 (2002) , “Divacancy in 3C- and 4H-SiC: An extremely stable defect”, L. Torpo, T. E. M. Staab, R. M. NieminenUsing first-principles calculations for divacancy defects in 3C- and 4H-SiC, we determine their formation energies and stability, their ionization levels, and relaxed geometries (symmetry point groups) for neutral as well as for charged states. For 4H-SiC all four possible nearest-neighbor divacancy... (Read more)
- 45. J. Phys.: Condens. Matter 13, 6203-6231 (2001) , “Comprehensive ab initio study of properties of monovacancies and antisites in 4H-SiC”, L. Torpo, M. Marlo, T. E. M. Staab, R. M. NieminenWe present results of ab initio calculations for the electronic and atomic structures of monovacancies and antisite defects in 4H-SiC in all possible charge states. The calculations make use of a plane-wave pseudopotential method based on density-functional theory and the local spin-density... (Read more)
- 46. Phys. Rev. B 64, 245212 (2001) , “Structure of the silicon vacancy in 6H-SiC after annealing identified as the carbon vacancy-carbon antisite pair”, Th. Lingner, S. Greulich-Weber, J.-M. Spaeth, U. Gerstmann, E. Rauls, Z. Hajnal, Th. Frauenheim, H. OverhofWe investigated radiation-induced defects in neutron-irradiated and subsequently annealed 6H-silicon carbide (SiC) with electron paramagnetic resonance (EPR), the magnetic circular dichroism of the absorption (MCDA), and MCDA-detected EPR (MCDA-EPR). In samples annealed beyond the annealing... (Read more)
- 47. Phys. Rev. B 64, 245208 (2001) , “Ab initio and empirical-potential studies of defect properties in 3C-SiC”, Fei Gao, Eric J. Bylaska, William J. Weber, L. René CorralesDensity functional theory (DFT) is used to study the formation and properties of native defects in 3C-SiC. Extensive calculations have been carried out to determine the formation of point defects and the stability of self-interstitials. Although there is good agreement in the formation of vacancies... (Read more)
- 48. Phys. Rev. B 63, 245202 (2001) , “Ab initio density-functional supercell calculations of hydrogen defects in cubic SiC”, B. Aradi, A. Gali, P. Deák, J. E. Lowther, N. T. Son, E. Janzén, W. J. ChoykeBased on ab initio density-functional calculations in supercells of 3C-SiC, the stable configurations of hydrogen and dihydrogen defects have been established. The calculated formation energies are used to give semiquantitative estimates for the concentration of hydrogen in SiC after chemical vapor... (Read more)
- 49. Physica B 308-310, 637 (2001) , “Calculation of hyperfine parameters of positively charged carbon vacancy in SiC”, T. T. Petrenko, T. L. Petrenko, V. Ya. Bratus and J. L. MongeTheoretical simulation of hyperfine parameters for the nearest and next-nearest neighbor atoms of VC+ in SiC has been performed for the cubic and hexagonal clusters. The gradient-corrected all-electron DFT calculations with Becke's three-parameter functional have been performed by the use of split... (Read more)
- 50. Physica B 308-310, 621 (2001) , “Positively charged carbon vacancy in 6H–SiC: EPR study”, V. Ya. Bratus, I. N. Makeeva, S. M. Okulov, T. L. Petrenko, T. T. Petrenko and H. J. von BardelebenThe low-temperature X-band EPR study of Ky1 and Ky2 centers assigned to positively charged carbon vacancy (VC+) in two quasicubic sites of 6H–SiC crystal is presented. The CS symmetry, spin S=1/2 and close coincidence of the g-tensor components have been revealed. The principal values of... (Read more)
- 51. J. Phys.: Condens. Matter 12, 3369 (2000) , “Local electronic structure around vacancies and vacancy-antisite complexes in ?-SiC”, G. Cubiotti, Yu. Kucherenko, A. Yaresko, A. Perlov, V. AntonovThe local electronic structure around vacancies and vacancy-antisite complexes in cubic SiC has been calculated by means of the LMTO (linear muffin-tin orbital) method and the supercell approach. In order to improve the description of the electronic structure near the energy gap, the... (Read more)
- 52. Phys. Rev. B 62, 6854 (2000) , “Spin state of vacancies: From magnetic Jahn-Teller distortions to multiplets”, A. Zywietz, J. Furthmüller, and F. BechstedtThe spin configuration of isoelectronic vacancies surrounded by first-row atoms is studied within density-functional theory (DFT) using the local spin density approximation. Allowing for a symmetry break in the electronic system, a mixed-spin state is found to be lowest in energy. It is accompanied... (Read more)
- 53. Phys. Rev. B 61, 13655 (2000) , “Intravacancy transition energies in 3C- and 4H-SiC”, A. Zywietz, J. Furthmüller, F. BechstedtSpin-polarized ab initio calculations are used to determine energy differences between ground and excited states of silicon and carbon vacancies in 3C- and 4H-SiC. The calculated transition energies are compared with recent findings from photoluminescence and magnetic-resonance experiments. (Read more)
- 54. Phys. Rev. B 61, 12939 (2000) , “Dimer of Substitutional Carbon in Silicon Studied by EPR and ab initio Methods”, J. R. Byberg, B. Bech Nielsen, M. Fanciulli, S. K. Estreicher, P. A. Fedders.An EPR signal observed in carbon-doped float-zone silicon after irradiation with 2-MeV electrons at room temperature has been investigated. It represents a defect with S=1/2, an apparently isotropic g factor (=2.0030), and a complicated hyperfine structure from 29Si nuclei in five shells... (Read more)
- 55. Phys. Rev. B 61, 12602 (2000) , “Phosphorus-related deep donor in SiC”, A. Gali, P. Deák, P. R. Briddon, R. P. Devaty, W. J. ChoykeTwo phosphorus centers in SiC, an isolated P atom substituting for Si (PSi) and a Si-site P-atom adjacent to a carbon vacancy (PSi+VC) are investigated by first principle calculations. It is shown that PSi+VC produces a singly occupied donor... (Read more)
- 56. Mater. Sci. Eng. B 61-62, 593 (1999) , “Electronic structure of the anti-structure pair in 3C–SiC”, L. Torpo and R. M. NieminenWe have studied the anti-structure pair (adjacent carbon CSi and silicon SiC antisites) in 3C–SiC using the plane–wave pseudopotential method. We report results for the formation energies, the ionization levels and the geometry of the relaxed structures of the defect in all its... (Read more)
- 57. Phys. Rev. B 59, 15166 (1999) , “Vacancies in SiC: Influence of Jahn-Teller distortions, spin effects, and crystal structure”, A. Zywietz, J. Furthmüller, and F. BechstedtWe present results of first-principles calculations for the neutral and charged Si and C monovacancies in cubic (3C) and hexagonal (4H) SiC. The calculations are based on the density functional theory in the local-density approximation as well as local spin density approximation. Explicitly a... (Read more)
- 58. phys. stat. sol. (b) 210, 13 (1999) , “Neutral Vacancies in Group-IV Semiconductors”, A. Zywietz, J. FurthmĂźller, F. BechstedtAb initio plane-wave-supercell calculations are performed for the neutral monovacancies in silicon, silicon carbide and diamond using ultrasoft non-normconserving Vanderbilt pseudopotentials. We study the structure, the energetics and the single-particle energy spectrum. The local symmetry, the... (Read more)
- 59. Phys. Rev. B 58, 9845 (1998) , “Theory of Carbon-Carbon Pairs in Silicon”, R. B. Capaz, A. Dal Pino, Jr., J. D. Joannopoulos.Interstitial-substitutional carbon pairs (CiCs) in silicon display interesting metastable behavior associated with two different structural configurations. In this work, we perform extensive ab initio calculations on this system. Our results show the following. (i) The... (Read more)
- 60. phys. stat. sol. (b) 210, 13 (1998) , “Neutral Vacancies in Group-IV Semiconductors”, A. Zywietz, J. Furthmüller, F. BechstedtAb initio plane-wave-supercell calculations are performed for the neutral monovacancies in silicon, silicon carbide and diamond using ultrasoft non-normconserving Vanderbilt pseudopotentials. We study the structure, the energetics and the single-particle energy spectrum. The local symmetry, the... (Read more)
- 61. Phys. Rev. B 55, 2188-2194 (1997) , “Dynamic Properties of Interstitial Carbon and Carbon-Carbon Pair Defects in Silicon”, P. Leary, R. Jones, S. Öberg, V. J. B. Torres.Interstitial carbon, Ci, defects in Si exhibit a number of unexplained features. The Ci defect in the neutral charge state gives rise to two almost degenerate vibrational modes at 920 and 931 cm-1 whose 2:1 absorption intensity ratio naturally suggests a trigonal... (Read more)
- 62. phys. stat. sol. (a) 162, 95-151 (1997) , “EPR and ENDOR Investigations of Shallow Impurities in SiC Polytypes”, S. Greulich-WeberInvestigations of nitrogen donors in 6H-, 4H- and 3C-SiC using conventional electron paramagnetic resonance (EPR), electron nuclear double resonance (ENDOR) and optical detection of EPR and ENDOR as well as optical absorption and emission spectroscopy are reviewed and critically discussed. An... (Read more)
- 63. Phys. Rev. B 47, 3620-3625 (1993) , “{H,B}, {H,C}, and {H,Si} pairs in silicon and germanium”, Dj. M. Maric, P. F. Meier, S. K. EstreicherThe interactions between interstitial H and substitutional B, C, and Si in crystalline silicon and germanium are studied in molecular clusters at the ab initio Hartree-Fock level with large basis sets. The energetics, electronic structures, and relative stabilities of these pairs are determined. Our... (Read more)
- 64. Phys. Rev. B 38, 12752(R) (1988) , “Formation energies, abundances, and the electronic structure of native defects in cubic SiC”, C. Wang, J. Bernholc, R. F. DavisThe relative abundance of native point defects in cubic SiC has been studied via ab initio calculations as a function of composition and the Fermi-level position. For Si-rich cubic SiC, the SiC antisite is the dominant defect in n-type material, while the carbon vacancy, which is a double... (Read more)
- 65. Sov. Phys. Solid State 23, 2126 (1981) , “Electron spin resonance of exchange-coupled vacancy pairs in hexagonal silicon carbide”, V. S. Va?ner, V. A. llin
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