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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. 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)
- 4. 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)
- 5. J. Appl. Phys. 96, 2406-2408 (2004) , “Annealing behavior of the carbon vacancy in electron-irradiated 4H-SiC”, Z. Zolnai, N. T. Son, C. Hallin, and E. JanzénElectron paramagnetic resonance (EPR) was used to study the annealing behavior of the positively charged carbon vacancy (EI5 center) in electron-irradiated 4H-SiC. At ~1000 °C the EPR signal of the defect starts decreasing gradually. Clear ligand hyperfine structure is still observed after... (Read more)
- 6. Mater. Sci. Forum 457-460, 465 (2004) , “EPR and pulsed ENDOR study of EI6 and related defects in 4H-SiC”, T. Umeda, Y. Ishitsuka, J. Isoya, N. Morishita, T. Ohshima, T. Kamiya
- 7. 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)
- 8. Phys. Rev. B 69, 121201(R) (2004) , “EPR identification of two types of carbon vacancies in 4H-SiC”, T. Umeda, J. Isoya, N. Morishita, T. Ohshima, and T. KamiyaThe EI5 and EI6 centers are typical intrinsic defects in radiation-damaged and semi-insulating 4H-SiC. So far, their origins have been assigned to positively charged carbon vacancies (VC+) and silicon antisites (SiC+), respectively. However,... (Read more)
- 9. Phys. Rev. Lett. 91, 109601 (2003) , “Comment on "Identification of Lattice Vacancies on the Two Sublattices of SiC"”, J. W. SteedsA Comment on the Letter by A. A. Rempel et al., Phys. Rev. Lett. 89, 185501 (2002). The authors of the Letter offer a Reply.... (Read more)
- 10. Appl. Phys. Lett. 81, 3945 (2002) , “Photoexcitation-electron-paramagnetic-resonance studies of the carbon vacancy in 4H-SiC”, N. T. Son, B. Magnusson, and E. JanzénPhotoexcitation-electron-paramagnetic-resonance (photo-EPR) studies were performed on p-type 4H-SiC irradiated with 2.5 MeV electrons. At W-band frequencies (~95 GHz) different EPR spectra could be well separated, allowing a reliable determination of the ground state levels of the... (Read more)
- 11. Phys. Rev. B 63, 201201(R) (2001) , “Carbon vacancy-related defect in 4H and 6H SiC”, N. T. Son, P. N. Hai, E. JanzénAn electron paramagnetic resonance (EPR) spectrum was observed at temperatures above 25 K in p-type 4H and 6H SiC irradiated with electrons. The center has C3V symmetry with an electron spin S=1/2. Using high frequency (?95 GHz) EPR it was possible to obtain the detailed hyperfine... (Read more)
- 12. Phys. Rev. Lett. 87, 45502 (2001) , “Silicon Antisite in 4H SiC”, N. T. Son, P. N. Hai, E. JanzénElectron paramagnetic resonance spectrum with C3V symmetry and a spin S = 1/2 has been observed in p-type, electron-irradiated 4H SiC. Based on the observed 29Si hyperfine structures it is suggested that the defect is the isolated silicon antisite (SiC). The spin... (Read more)
- 13. 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)
- 14. Phys. Rev. B 62, 10841 (2000) , “Vacancy defects in p-type 6H-SiC created by low-energy electron irradiation”, H. J. von Bardeleben, J. L. Cantin, L. Henry, M. F. BartheThe intrinsic defects in p-type 6H-SiC:Al generated by electron irradiation at 300 keV, which is close to the threshold of the silicon atom displacement, have been studied by electron paramagnetic resonance spectroscopy. We observed two dominant irradiation-induced paramagnetic defects:?(i) a... (Read more)
- 15. Phys. Rev. B 61, 2657 (2000) , “Divacancy-Tin Complexes in Electron-Irradiated Silicon Studied by EPR”, M. Fanciulli, J. R. Byberg.n- and p-type float-zone silicon containing 1018-cm-3 tin were irradiated with 2 MeV electrons to a dose of 1018 cm-2 and subsequently examined by electron paramagnetic resonance (EPR). The p-type material yields only the well-known Si-G29 signal due to... (Read more)
- 16. Mater. Sci. Eng. B 61-62, 202 (1999) , “Carbon-vacancy related defects in 4H- and 6H-SiC”, N. T. Son, W. M. Chen, J. L. Lindström, B. Monemar, E. JanzénElectron paramagnetic resonance (EPR) was used to study intrinsic defects in 4H- and 6H-SiC irradiated with 2.5 MeV electrons with doses ranging from 1×1017 to 2×1018 cm−2. In p-type 4H- and 6H-SiC, the dominant EPR signal, labeled EI1, associates with a defect centre having a low... (Read more)
- 17. Phys. Rev. B 51, 1928 (1995) , “Carbon and silicon vacancies in electron-irradiated 6H-SiC”, S. Dannefaer, D. Craigen, D. KerrPositron-lifetime and Doppler-broadening spectroscopies were used to investigate vacancies formed by 2.2- and 10-MeV electrons. Carbon vacancies yield a positron lifetime of 160 ps, only 15 ps longer than the bulk lifetime, and the Doppler-broadening S parameter is very close to that for the bulk.... (Read more)
- 18. Phys. Rev. B 38, 3395-3399 (1988) , “Electrical and Optical Properties of Defects in Silicon Introduced by High-Temperature Electron Irradiation”, Jian-Guo Xu, Fang Lu, and Heng-Hui Sun2-MeV electron irradiation of Si at elevated temperature creates a dominant deep level at the energy Ec-0.36 eV in addition to the oxygen vacancies. This level, which is less significant in room-temperature-irradiated Si, is found to be an efficient recombination center in the present... (Read more)
- 19. Phys. Rev. B 13, 2511 (1976) , “EPR of a Trapped Vacancy in Boron-Doped Silicon”, G. D. Watkins.An S=1/2 EPR spectrum, labeled Si-G10, is tentatively identified as a lattice vacancy trapped by substitutional boron in silicon. It is produced in boron-doped vacuum floating-zone silicon by 1.5-MeV-electron irradiation at 20.4 K followed by an anneal at ? 180 K, where the isolated vacancy... (Read more)
- 20. Lattice Defects in Semiconductors 23, 1-22 (1975) , Institute of Physics, London , “EPR Studies of the Lattice Vacancy and Low-Temperature Damage Processes in Silocon”, G. D. Watkins.EPR studies of silicon irradiated at 20.4 K and 4.2 K by 1.5 MeV and 46 MeV electrons are described. In 46 MeV irradiations the dominant defects formed appear to be divavancies and other multiple defect aggregates which liberate vacancies throughout the anneal to room temperature as they reorder, recombine, etc. For 1.5 MeV irradiations group III atoms play a vital role in p- and n-type materials in trapping interstitials and stabilizing damage. Carbon and oxygen are not effective interstitial traps at these temperatures. Evidence of limited vacancy migration during irradiation is also cited. Two distinct excited configurations of vacancy-oxygen pairs are identified as precursors to A-centre formation in n-type silicon. The kinetics for their conversion to A-centres depends strongly upon the Fermi level as does the isolated vacancy migration energy whhich is measured to be 0.18 Âą 0.02 eV for the Vďź charge state. The vacancy has four charge states, Vďź, V0, Vďź and Vďź. Kinetics for hole release from Vďź reveals an activation barrier of 0.057 eV. The concentration of Vďź at 20.4 K in boron-doped material indicates the corresponding donor level even closer to the band edge, approximately EV ďź 0.039 eV. Jahn-Teller energies for V0, Vďź, and Vďź are estimated from stress-alignment studies and confirmed to be large. Kinetics studies for reorientation from one Jahn-Teller distortion to another are also described for each charge state.
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