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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, 085416 (2007) , “Ab initio theoretical study of hydrogen and its interaction with boron acceptors and nitrogen donors in single-wall silicon carbide nanotubes”, A. GaliSilicon carbide nanotubes have a great potential for biological applications. It is of interest to explore the electronic properties of these nanotubes, and how those are modified in the presence of impurities. Hydrogen is a common impurity that can appear during the growth of silicon carbide... (Read more)
- 4. 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)
- 5. Phys. Rev. B 75, 045211 (2007) , “Ab initio supercell calculations on aluminum-related defects in SiC”, A. Gali, T. Hornos, N. T. Son, E. Janzén, and W. J. ChoykeAb initio supercell calculations of the binding energies predict complex formation between aluminum and carbon interstitials in SiC. In high-energy implanted SiC aluminum acceptor can form very stable complexes with two carbon interstitials. We also show that carbon vacancy can be attached to... (Read more)
- 6. Phys. Rev. Lett. 98, 026101 (2007) , “Bonding at the SiC-SiO2 Interface and the Effects of Nitrogen and Hydrogen”, Sanwu Wang, S. Dhar, Shu-rui Wang, A. C. Ahyi, A. Franceschetti, J. R. Williams, L. C. Feldman,, and Sokrates T. PantelidesUnlike the Si-SiO2 interface, the SiC-SiO2 interface has large defect densities. Though nitridation has been shown to reduce the defect density, the effect of H remains an open issue. Here we combine experimental data and the results of first-principles calculations to... (Read more)
- 7. Appl. Phys. Lett. 88, 082113 (2006) , “Effect of charge on the movement of dislocations in SiC”, T. A. G. Eberlein, R. Jones, A. T. Blumenau, S. Öberg, P. R. BriddonSiC bipolar devices show a degradation under forward-biased operation which has been linked with a current induced motion of one of the two glide dislocations having either Si or C core atoms. We have carried out calculations of the core structures and dynamics of partial dislocations in 3C and... (Read more)
- 8. J. Appl. Phys. 99, 011101 (2006) , “Degradation of hexagonal silicon-carbide-based bipolar devices”, M. Skowronski and S. HaOnly a few years ago, an account of degradation of silicon carbide high-voltage p-i-n diodes was presented at the European Conference on Silicon Carbide and Related Compounds (Kloster Banz, Germany, 2000). This report was followed by the intense effort of multiple groups... (Read more)
- 9. Phys. Rev. B 74, 245216 (2006) , “Influence of excited states of a deep substitutional dopant on majority-carrier concentration in semiconductors”, Hideharu MatsuuraThe density (NA) and energy level (EA) of an acceptor in a p-type wide-band-gap semiconductor (e.g., SiC, GaN, and diamond) are determined by a least-squares fit of the charge neutrality equation to the temperature dependence of the hole... (Read more)
- 10. Phys. Rev. B 74, 245212 (2006) , “Deactivation of nitrogen donors in silicon carbide”, F. Schmid, S. A. Reshanov, H. B. Weber, G. Pensl, M. Bockstedte, A. Mattausch, O. Pankratov, T. Ohshima, and H. ItohHexagonal SiC is either co-implanted with silicon (Si+), carbon (C+), or neon (Ne+) ions along with nitrogen (N+) ions or irradiated with electrons (e−) of 200 keV energy. During the subsequent annealing step at temperatures above 1450 ... (Read more)
- 11. Phys. Rev. B 74, 155425 (2006) , “Ab initio study of native defects in SiC nanotubes”, R. J. Baierle, P. Piquini, L. P. Neves, and R. H. MiwaSpin-polarized density functional theory is used to investigate the electronic and structural properties of vacancies and antisites in zigzag, armchair, and chiral SiC nanotubes. Antisites present lower formation energies compared to vacancies, introducing an empty electronic level close to the... (Read more)
- 12. Phys. Rev. B 74, 144106 (2006) , “Density functional theory calculation of the DI optical center in SiC”, T. A. G. Eberlein, R. Jones, S. Öberg, and P. R. BriddonThe DI center is a prominent defect which is detected in as-grown or irradiated SiC. It is unusual in that its intensity grows with heat treatments and survives anneals of 1700 °C. It has been assigned recently to either a close-by antisite pair or to the close-by antisite... (Read more)
- 13. Phys. Rev. B 73, 245415 (2006) , “Ab initio study of nitrogen and boron substitutional impurities in single-wall SiC nanotubes”, A. GaliSilicon carbide nanotubes have a great potential for application in chemical sensors in harsh environment or in biological sensors. It is of interest to explore the electronic properties of these nanotubes, and how those are modified in the presence of impurities. It is well known that nitrogen and... (Read more)
- 14. 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)
- 15. Phys. Rev. B 73, 125206 (2006) , “Atomistic simulations on the thermal stability of the antisite pair in 3C- and 4H-SiC”, M. Posselt, F. Gao, W. J. WeberThe thermal stability of the first-neighbor antisite pair configurations in 3C- and 4H-SiC is investigated by atomic-level computer simulations. First, the structure and energetics of these defects are determined in order to check the accuracy of the interatomic potential employed. The results are... (Read more)
- 16. Phys. Rev. B 73, 075201 (2006) , “Electron paramagnetic resonance and theoretical studies of shallow phosphorous centers in 3C-, 4H-, and 6H-SiC”, N. T. Son, A. Henry, J. Isoya, M. Katagiri, T. Umeda, A. Gali, E. JanzénContinuous-wave (cw) electron paramagnetic resonance (EPR) at both X-band and W-band frequencies, pulsed-EPR, and pulsed electron nuclear double resonance (ENDOR) were used to study phosphorus shallow donors in 3C-, 4H-, and 6H-SiC doped with phosphorus (P) during... (Read more)
- 17. 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)
- 18. 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)
- 19. 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
- 20. Physica B 376-377, 358-361 (2006) , “Pulsed EPR studies of Phosphorus shallow donors in diamond and SiC”, J. Isoya, M. Katagiri, T. Umeda, S. Koizumi, H. Kanda, N. T. Son, A. Henry, A. Gali, E. JanzénPhosphorus shallow donors having the symmetry lower than Td are studied by pulsed EPR. In diamond:P and 3C–SiC:P, the symmetry is lowered to D2d and the density of the donor wave function on the phosphorus atom exhibits a predominant p-character. In 4H–SiC:P with the site symmetry of... (Read more)
- 21. 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)
- 22. 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)
- 23. 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)
- 24. 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)
- 25. 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)
- 26. 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)
- 27. 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)
- 28. 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)
- 29. 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)
- 30. 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)
- 31. 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)
- 32. 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)
- 33. 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)
- 34. 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)
- 35. Phys. Rev. B 69, 233202 (2004) , “Diffusion of hydrogen in perfect, p-type doped, and radiation-damaged 4H-SiC”, B. Aradi, P. Deák, A. Gali, N. T. Son, E. JanzénThe diffusion of interstitial atomic hydrogen in 4H-SiC was investigated theoretically, using the local density approximation of density functional theory. We have found that the diffusion barrier in the perfect crystal is 0.6 eV. Comparing this value with the calculated zero point vibration... (Read more)
- 36. 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)
- 37. 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)
- 38. 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)
- 39. 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)
- 40. Phys. Rev. B 68, 125204 (2003) , “Magnetic properties of substitutional 3d transition metal impurities in silicon carbide”, M. S. Miao and Walter R. L. LambrechtUsing the linearized muffin-tin orbital (LMTO) method within both the atomic sphere approximation and full potential (FP) implementations and within the local spin-density-functional method and a supercell approach, we study the magnetic properties of cubic (3C) silicon carbide (SiC) doped by... (Read more)
- 41. 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)
- 42. 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)
- 43. 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)
- 44. 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)
- 45. Phys. Rev. B 67, 165212 (2003) , “Optical selection rules for shallow donors in 4H-SiC and ionization energy of the nitrogen donor at the hexagonal site”, I. G. Ivanov, B. Magnusson, and E. JanzénThe selection rules for transitions between the electronic levels of shallow donors in 4H-SiC in the dipole approximation are derived. The ionization energy of the shallow nitrogen donor (at hexagonal site) is determined to be 61.4±0.5 meV by analyzing the photothermal ionization and... (Read more)
- 46. 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)
- 47. 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)
- 48. 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)
- 49. 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)
- 50. J. Appl. Phys. 92, 889-894 (2002) , “Ramification of micropipes in SiC crystals”, M. Yu. Gutkin, A. G. Sheinerman, T. S. Argunova, J. H. Je, H. S. Kang, Y. Hwu, W.-L. TsaiThe ramification of micropipes is observed using scanning electron microscopy, optical microscopy, and synchrotron x-ray radiography. The conditions for the ramification of dislocated micropipes are determined theoretically within a model when the angles between dislocation lines are small. It is... (Read more)
- 51. 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)
- 52. 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)
- 53. 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)
- 54. 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)
- 55. 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)
- 56. 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)
- 57. 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)
- 58. 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)
- 59. 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)
- 60. 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)
- 61. 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)
- 62. 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)
- 63. 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)
- 64. 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)
- 65. 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)
- 66. 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)
- 67. Phys. Rev. B 57, 6243 (1998) , “Antisites in silicon carbide”, L. Torpo, S. Pöykkö, and R. M. NieminenTen years ago, deep-level-transient-spectroscopy (DLTS) signals, assigned to centers labeled as H1, H2, H3, and E2, have been detected in neutron-irradiated 3C SiC. The H centers were believed to be the primary point defects and the E2 center a secondary defect, which forms after the H centers start... (Read more)
- 68. phys. stat. sol. (b) 210, 415-427 (1998) , “The Microscopic and Electronic Structure of Shallow Donors in SiC”, S. Greulich-WeberNitrogen donors in 6H-, 4H- and 3C-SiC were investigated using conventional electron paramagnetic resonance (EPR) and electron nuclear double resonance (ENDOR) and the experimental results are discussed. An attempt is presented to interpret the experimentally found large differences in hyperfine... (Read more)
- 69. 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)
- 70. Phys. Rev. B 56, 7384 (1997) , “Negatively charged Si vacancy in 4H SiC: A comparison between theory and experiment”, T. Wimbauer, B. K. Meyer, A. Hofstaetter, A. Scharmann, H. OverhofWe use electron paramagnetic resonance and electron nuclear double resonance to identify the negatively charged Si vacancy in neutron-irradiated 4H SiC. The identification is based on resolved ligand hyperfine interactions with carbon and silicon nearest and next nearest neighbors and on the... (Read more)
- 71. 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)
- 72. 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)
- 73. 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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