Results 191 to 200 of about 240,009 (234)

The D1 Exciton in 4H-SiC

physica status solidi (b), 1998
We report on the properties of the D1 photoluminescence (PL) observed in electron irradiated 4H-SiC. We have investigated the temperature dependence of the PL and its excitation properties. At 2 K the D1 PL spectrum in 4H-SiC consists of one no-phonon line, L1 (2.9010 eV), and its phonon replicas.
T. Egilsson, J.P. Bergman, I.G. Ivanov, A. Henry, E. Janz�n   +4 more
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Photoluminescence upconversion in 4H–SiC

Applied Physics Letters, 2002
Efficient photoluminescence upconversion is observed in 4H–SiC samples containing both the UD-3 defect and the titanium impurity. In this process, the titanium photoluminescence emission with no-phonon (NP) lines at 2.848 eV (A0) and 2.789 eV (B0) can be excited by tuning the laser to the NP line of UD-3 at 1.356 eV.
Mt. Wagner, I. G. Ivanov, L. Storasta, J. P. Bergman, B. Magnusson, W. M. Chen, E. Janzén   +6 more
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Boron Centers in 4H-SiC

Materials Science Forum, 2001
The origin of the "deep boron related acceptor level" in SIC is subject to a lot of controversy. Based on ENDOR investigations, a B-Si+V-C model was suggested, while PL studies indicated the acceptor on the carbon sublattice. Our former ab initio LDA molecular cluster calculation showed that in the B-Si+V-C complex the carbon vacancy acts as the ...
B. Aradi, Adam Gali, Peter Deák, E. Rauls, Thomas Frauenheim, Nguyen Tien Son   +5 more
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Investigation of the 4H–SiC surface

Applied Surface Science, 2008
Abstract The silicon carbide (SiC) surface is more complex than that of silicon and can be carbon-terminated or silicon-terminated, and can exist as several reconstructions. Investigations of the surface structure as a function of temperature, under ultrahigh vacuum (UHV) conditions using scanning tunneling microscopy (STM) and low energy electron ...
O.J. Guy, M. Lodzinski, K.S. Teng, T.G.G. Maffeis, M. Tan, I. Blackwood, P.R. Dunstan, O. Al-Hartomy, S.P. Wilks, T. Wilby, N. Rimmer, D. Lewis, J. Hopkins   +12 more
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Optical properties of 4H–SiC

Journal of Applied Physics, 2002
The optical band gap energy and the dielectric functions of n-type 4H–SiC have been investigated experimentally by transmission spectroscopy and spectroscopic ellipsometry and theoretically by an ab initio full-potential linear muffin-tin-orbital method.
R. Ahuja, A. Ferreira da Silva, C. Persson, J. M. Osorio-Guillén, I. Pepe, K. Järrendahl, O. P. A. Lindquist, N. V. Edwards, Q. Wahab, B. Johansson   +9 more
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4H-SiC power TCAD

IEE Colloquium on New Developments in Power Semiconductor Devices, 1996
Physical models of material properties for 4H-SiC TCAD have been presented and used to discuss modelling of a selection of Power Semiconductor Devices. Such TCAD techniques have been utilised to quantify the expected switching speed performance of SiC MESFETs.
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Monovacancies in 3C and 4H SiC

Materials Science and Engineering: B, 1999
We present first-principles calculations of the atomic and electronic structure of neutral and charged C and Si vacancies in 3C and 4H SiC. We demonstrate that the principal properties of the vacancies depend only weakly on the polytype. In both polytypes the formation of C vacancies is accompanied by a significant symmetry-breaking distortion of the ...
J Furthmüller, A Zywietz, F Bechstedt
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Neutron Irradiation of 4H SiC

Materials Science Forum, 2001
The effect of neutron irradiation on 4H SiC epitaxial layers are studied. Several different doses of both fast and thermal neutrons have been used and the samples have been annealed from 500 degreesC to 2000 degreesC. The defect concentration dependence on the fast neutron flux and on the annealing temperature is investigated.
F.H.C. Carlsson, L. Storasta, Björn Magnusson, Peder Bergman, K. Sköld, Erik Janzén   +5 more
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SiC Pore Surfaces: Surface Studies of 4H-SiC(1-102) and 4H-SiC(-110-2)

Materials Science Forum, 2006
The morphology and atomic structure of 4H-SiC(1102) and 4H-SiC(1102) surfaces, i.e. the surfaces found in the triangular channels of porous 4H-SiC, have been investigated using AFM, LEED and AES. After hydrogen etching the surfaces show steps parallel and perpendicular to the caxis, yet drastically different morphologies for the two isomorphic ...
Starke, U., Lee, W., Coletti, C., Saddow, S., Devaty, R., Choyke, W.   +5 more
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Raman Spectra of a 4H-SiC Epitaxial Layer on Porous and Non-Porous 4H-SiC Substrates

Materials Science Forum, 2007
A lightly doped n-type homo-epitaxial layer was grown by CVD onto a heavily doped n-type 4H-SiC substrate for which half of the surface had been made porous by photoelectrochemical etching. Raman spectra are obtained in the optic phonon region using three scattering geometries.
M.J. Clouter, Yue Ke, Robert P. Devaty, W.J. Choyke, Y. Shishkin, S.E. Saddow   +5 more
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