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  • 151.
    Khranovskyy, Volodymyr
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, The Institute of Technology.
    Yakimova, Rositsa
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, The Institute of Technology.
    Karlsson, Fredrik
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, The Institute of Technology.
    Syed, Abdul S
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, The Institute of Technology.
    Holtz, Per-Olof
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, The Institute of Technology.
    Nigussa Urgessa, Zelalem
    Nelson Mandela Metropolitan University, South Africa.
    Oluwafemi, Oluwatobi Samuel
    Walter Sisulu University, South Africa.
    Reinhardt Botha, Johannes
    Nelson Mandela Metropolitan University, South Africa.
    Comparative PL study of individual ZnO nanorods, grown by APMOCVD and CBD techniques2012In: Physica. B, Condensed matter, ISSN 0921-4526, E-ISSN 1873-2135, Vol. 407, no 10, p. 1538-1542Article in journal (Refereed)
    Abstract [en]

    The photoluminescence properties of individual ZnO nanorods, grown by atmospheric pressure metalorganic chemical vapor deposition (APMOCV) and chemical bath deposition (CBD) are investigated by means of temperature dependent micro-PL. It was found that the low temperature PL spectra are driven by neutral donor bound exciton emission (DX)-X-0, peaked at 3.359 and 3.363 eV for APMOCVD and CBD ZnO nanorods, respectively. The temperature increase causes a red energy shift of the peaks and enhancement of the free excitonic emission (FX). The FX was found to dominate after 150 K for both samples. It was observed that while APMOCVD ZnO nanorods possess a constant low signal of visible deep level emission with temperature, the ZnO nanorods grown by CBD revealed the thermal activation of deep level emission (DLE) after 130 K. The resulting room temperature DLE was a wide band located at 420-550 nm. The PL properties of individual ZnO nanorods can be of importance for their forthcoming application in future optoelectronics and photonics.

  • 152.
    Khranovskyy, Volodymyr
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, Faculty of Science & Engineering.
    Yakimova, RositzaLinköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, Faculty of Science & Engineering.
    Book of Abstracts: 1st International Workshop on Functional Oxide (FOX) Materials2015Conference proceedings (editor) (Other academic)
    Abstract [en]

    Oxide semiconductors are an important part of the functional materials  field. Technological accessibility (physical & chemical synthesis), diversity of geometrical shapes (bulk, films, nanostructures) and environmental stability combined with ambience sensitivity makes them promising materials for plenty of future applications. Among other, ZnO, Al2O3, GaO, NiO, TiOx, Gd2O3, Fe3O4 and graphene oxide are considered as materials for both active and passive components in many applications: transparent conductive coatings, gas sensors, biosensors, tomography markers, light emitters, thermoelectric materials, catalysts and many others. We expect the experts to present their latest results on fabrication, characterization and application of the oxide materials.

  • 153.
    Khranovskyy, Volodymyr
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials.
    Yazdi, Gholamreza
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials.
    Larsson, Arvid
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials.
    Hussain, S
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, The Institute of Technology.
    Holtz, Per-Olof
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials.
    Yakimova, Rositsa
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials.
    Growth and characterization of ZnO nanostructured material2008In: Journal of Optoelectronics and Advanced Materials, ISSN 1454-4164, E-ISSN 1841-7132, Vol. 10, no 11, p. 2969-2975Article in journal (Refereed)
    Abstract [en]

    ZnO is a wide band gap (3.37 eV) semiconductor material with a high exciton binding energy (60 meV) at room temperature, which is a prerequisite for realization of efficient and stable optoelectronic systems. We demonstrated the APMOCVD growth of nanostructured ZnO material on Si and SiC with advanced emitting properties. The comparison of the properties of nanostructured polycrystalline layers with spatially disconnected ZnO nanocrystals clearly showed the advantage of the latter structures. Such structures distinctively luminesce in the UV range of the spectrum due to excitonic emission, while the contribution of the defect related luminescence is negligible. The significant improvement of the PL properties can be related to the decreased number of non-radiative recombination centers in the nanocrystals of high structural quality.

  • 154.
    Khranovskyy, Volodymyr
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials.
    Yazdi, Gholamreza
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials.
    Lashkarev, G.
    Inst Problems Mat Sci, UA-03680 Kiev, Ukraine.
    Ulyashin, A.
    Inst Energy Technol, N-2027 Kjeller, Norway.
    Yakimova, Rositsa
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials.
    Investigation of ZnO as a perspective material for photonics2008In: Physica Status Solidi (a) applications and materials science, ISSN 1862-6300, E-ISSN 1862-6319, Vol. 205, no 1, p. 144-149Article in journal (Refereed)
    Abstract [en]

    Emissive properties of ZnO are of great interests in terms of the UV LED device design. The persistent "green" luminescence due to deep defect is an obstacle for obtaining an intense UV emission, expected from ZnO. We report the positive role of thermally diffused H toward quenching the defect emission in ZnO. It is suggested that hydrogen passivates defects responsible for DLE, resulting in efficient near band edge luminescence. As-grown ZnO/SiNx :H/Si films, deposited at 350 degrees C demonstrate intense narrow peaks of UV emission at 380 nm and a ratio of emission intensities, NBE/DLE approximate to 42. [GRAPHICS]

  • 155. Kihlgren, T.
    et al.
    Balasubramanian, T.
    Wallden, L.
    Yakimova, Rositsa
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Materials Science .
    K/graphite: Uniform energy shifts of graphite valence states2006In: Surface Science, ISSN 0039-6028, E-ISSN 1879-2758, Vol. 600, no 5, p. 1160-1164Article in journal (Refereed)
    Abstract [en]

    Ultra-thin graphite overlayers prepared by heating SiC crystals can give highly resolved valence band photoemission spectra. This is exploited to monitor K deposition induced energy shifts of graphite valence band states. States near the corners of the Brillouin zone, responsible for the semimetal character of graphite, are observed to show shifts that are nearly equal to the shifts of the uppermost filled σ state and of an empty state 7.6 eV above E F. The results give credence to the rigid band shift model often used to discuss the electronic structure and charge transfer for graphite ad- and absorption systems. © 2006 Elsevier B.V. All rights reserved.

  • 156. Kihlgren, T
    et al.
    Balasubramanian, T
    Wallden, L
    Yakimova, Rositsa
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Materials Science .
    Narrow photoemission lines from graphite valence states2002In: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 66, no 23Article in journal (Refereed)
    Abstract [en]

    Valence-band photoelectron angular distributions, measured in the photon energy range 20-150 eV, are obtained from crystalline graphite overlayers prepared by heating SiC(0001) and from a graphite natural single crystal. The dispersion of the valence bands for the overlayers agrees well with that of the single crystal. The valence electrons have binding energies, which agree with LDA calculations if the calculated binding energies are multiplied by a factor of 1.13. The upper sigma state at Gamma and states near the Fermi level at the zone corners give quite narrow emission lines. Since the widths are on par with that of the C 1s level the lines are of interest as an alternative to the core line when graphite is used as substrate for adsorption or absorption studies.

  • 157. Kiselov, V.S.
    et al.
    Kalabukhova, E.N.
    Lukin, S.N.
    Sitnikov, A.A.
    Yukhymchyk, V.A.
    Yakimova, Rositsa
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Materials Science .
    Optical and Electron Paramagnetic Resonance Study of Sponge Silicon Carbide Prepared by Direct Synthesis2007In: ECSCRM 2006,2006, Material Science Forum, vol. 556-557: Trans Tech Publications , 2007, p. 399-Conference paper (Refereed)
  • 158.
    Kovacs, Andras
    et al.
    Forschungszentrum Julich, Germany; Forschungszentrum Julich, Germany.
    Duchamp, Martial
    Forschungszentrum Julich, Germany; Forschungszentrum Julich, Germany.
    Dunin-Borkowski, Rafal E.
    Forschungszentrum Julich, Germany; Forschungszentrum Julich, Germany.
    Yakimova, Rositsa
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, The Institute of Technology.
    Neumann, Peter L.
    Hungarian Academic Science, Hungary.
    Behmenburg, Hannes
    AIXTRON SE, Germany.
    Foltynski, Bartosz
    AIXTRON SE, Germany.
    Giesen, Cristoph
    AIXTRON SE, Germany.
    Heuken, Michael
    AIXTRON SE, Germany.
    Pecz, Bela
    Hungarian Academic Science, Hungary.
    Graphoepitaxy of High-Quality GaN Layers on Graphene/6H-SiC2015In: ADVANCED MATERIALS INTERFACES, ISSN 2196-7350, Vol. 2, no 2Article in journal (Refereed)
    Abstract [en]

    The implementation of graphene layers in gallium nitride (GaN) heterostructure growth can solve self-heating problems in nitride-based high-power electronic and light-emitting optoelectronic devices. In the present study, high-quality GaN layers are grown on patterned graphene layers and 6H-SiC by metalorganic chemical vapor deposition. A periodic pattern of graphene layers is fabricated on 6H-SiC by using polymethyl methacrylate deposition and electron beam lithography, followed by etching using an Ar/O-2 gas atmosphere. Prior to GaN growth, an AlN buffer layer and an Al0.2Ga0.8N transition layer are deposited. The atomic structures of the interfaces between the 6H-SiC and graphene, as well as between the graphene and AlN, are studied using scanning transmission electron microscopy. Phase separation of the Al0.2Ga0.8N transition layer into an AlN and GaN superlattice is observed. Above the continuous graphene layers, polycrystalline defective GaN is rapidly overgrown by better quality single-crystalline GaN from the etched regions. The lateral overgrowth of GaN results in the presence of a low density of dislocations (approximate to 10(9) cm(-2)) and inversion domains and the formation of a smooth GaN surface.

  • 159.
    Kuehne, P
    et al.
    University of Nebraska, NE USA.
    Darakchieva, Vanya
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, The Institute of Technology.
    Yakimova, Rositsa
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, The Institute of Technology.
    Tedesco, J D.
    ABB Inc, VA USA.
    Myers-Ward, R L.
    US Naval Research Lab, DC USA.
    Jr Eddy, C R.
    US Naval Research Lab, DC USA.
    Gaskill, D K.
    US Naval Research Lab, DC USA.
    Herzinger, C M.
    JA Woollam Co Inc, NE USA.
    Woollam, J A.
    JA Woollam Co Inc, NE USA.
    Schubert, M
    University of Nebraska, NE USA.
    Hofmann, T
    University of Nebraska, NE USA.
    Polarization Selection Rules for Inter-Landau-Level Transitions in Epitaxial Graphene Revealed by the Infrared Optical Hall Effect2013In: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 111, no 7, p. e077402-Article in journal (Refereed)
    Abstract [en]

    We report on the polarization selection rules of inter-Landau-level transitions using reflection-type optical Hall effect measurements from 600 to 4000  cm-1 on epitaxial graphene grown by thermal decomposition of silicon carbide. We observe symmetric and antisymmetric signatures in our data due to polarization preserving and polarization mixing inter-Landau-level transitions, respectively. From field-dependent measurements, we identify that transitions in coupled graphene monolayers are governed by polarization mixing selection rules, whereas transitions in decoupled graphene monolayers are governed by polarization preserving selection rules. The selection rules may find explanation by different coupling mechanisms of inter-Landau-level transitions with free charge carrier magneto-optic plasma oscillations.

  • 160.
    Kwasnicki, Pawel
    et al.
    CNRS, L2C UMR 5221, F-34095, Montpellier, France.
    Jokubavicius, Valdas
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, The Institute of Technology.
    Sun, Jianwu
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, The Institute of Technology.
    Peyre, H.
    Université Montpellier 2, L2C UMR 5221, F-34095, Montpellier, France .
    Yakimova, Rositsa
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, The Institute of Technology.
    Syväjärvi, Mikael
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, The Institute of Technology.
    Camasse, J.
    CNRS, L2C UMR 5221, F-34095, Montpellier, France .
    Juillaguet, S.
    Université Montpellier 2, L2C UMR 5221, F-34095, Montpellier, France.
    Optical investigation of 3C-SiC hetero-epitaxial layers grown by sublimation epitaxy under gas atmosphere2014In: Materials Science Forum, ISSN 0255-5476, E-ISSN 1662-9752, Vol. 778-780, p. 243-246Article in journal (Refereed)
    Abstract [en]

    We investigated three 3C-SiC samples grown on 6H SiC substrate by sublimation epitaxy under gas atmosphere. We focus on the low temperature photoluminescence and Raman measurements to show that compare to a growth process under vacuum atmosphere, the gas atmosphere favor the incorporation of impurities at already existing and/or newly created defect sites.

  • 161.
    Lara-Avila, Samuel
    et al.
    Chalmers, Sweden.
    Kubatkin, Sergey
    Chalmers, Sweden.
    Kashuba, Oleksiy
    Technical University of Dresden, Germany.
    Folk, Joshua A.
    University of British Columbia, Canada; University of British Columbia, Canada.
    Luescher, Silvia
    University of British Columbia, Canada; University of British Columbia, Canada.
    Yakimova, Rositsa
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, Faculty of Science & Engineering.
    Janssen, T. J. B. M.
    National Phys Lab, England.
    Tzalenchuk, Alexander
    National Phys Lab, England; University of London, England.
    Falko, Vladimir
    University of Lancaster, England.
    Influence of Impurity Spin Dynamics on Quantum Transport in Epitaxial Graphene2015In: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 115, no 10, p. 106602-Article in journal (Refereed)
    Abstract [en]

    Experimental evidence from both spin-valve and quantum transport measurements points towards unexpectedly fast spin relaxation in graphene. We report magnetotransport studies of epitaxial graphene on SiC in a vector magnetic field showing that spin relaxation, detected using weak-localization analysis, is suppressed by an in-plane magnetic field B-parallel to, and thereby proving that it is caused at least in part by spinful scatterers. A nonmonotonic dependence of the effective decoherence rate on B-parallel to reveals the intricate role of the scatterers spin dynamics in forming the interference correction to the conductivity, an effect that has gone unnoticed in earlier weak localization studies.

  • 162.
    Lara-Avila, Samuel
    et al.
    Chalmers.
    Moth-Poulsen, Kasper
    University of California Berkeley.
    Yakimova, Rositsa
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, The Institute of Technology.
    Bjornholm, Thomas
    University of Copenhagen.
    Falko, Vladimir
    University of Lancaster.
    Tzalenchuk, Alexander
    National Physics Lab, Teddingto.
    Kubatkin, Sergey
    Chalmers.
    Non-Volatile Photochemical Gating of an Epitaxial Graphene/Polymer Heterostructure2011In: ADVANCED MATERIALS, ISSN 0935-9648, Vol. 23, no 7, p. 878-+Article in journal (Refereed)
    Abstract [en]

    A novel heterostructure based on epitaxial graphene grown on silicon carbide combined with two polymers is demonstrated, with a neutral spacer and a photoactive layer that provides potent electron acceptors under UV light exposure. UV exposure of this heterostructure enables control of the electrical parameters of graphene in a non-invasive, non-volatile, and reversible way.

  • 163.
    Lara-Avila, Samuel
    et al.
    Chalmers.
    Tzalenchuk, Alexander
    National Physics Lab, England .
    Kubatkin, Sergey
    Chalmers.
    Yakimova, Rositsa
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, The Institute of Technology.
    Janssen, T J B M
    National Physics Lab, England .
    Cedergren, Karin
    Chalmers.
    Bergsten, Tobias
    Technical Research Institute of Sweden.
    Falco, Vladimir
    Lancaster University, United Kingdom .
    Disordered Fermi Liquid in Epitaxial Graphene from Quantum Transport Measurements2011In: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 107, no 16, p. 166602-Article in journal (Refereed)
    Abstract [en]

    We have performed magnetotransport measurements on monolayer epitaxial graphene and analyzed them in the framework of the disordered Fermi liquid theory. We have separated the electron-electron and weak-localization contributions to resistivity and demonstrated the phase coherence over a micrometer length scale, setting the limit of at least 50 ps on the spin relaxation time in this material.

  • 164.
    Larsson, Henrik
    et al.
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, The Institute of Technology.
    Gogova, Daniela
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, The Institute of Technology.
    Kasic, A.
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, The Institute of Technology.
    Yakimova, Rositsa
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, The Institute of Technology.
    Monemar, Bo
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, The Institute of Technology.
    Miskys, C. R.
    Walter Schottky Institut, Technische Universität Munchen, Germany.
    Stutzmann, M.
    Walter Schottky Institut, Technische Universität Munchen, Germany.
    Free-standing HVPE-GaN Layers2003In: Physica Status Solidi. C, Current topics in solid state physics, ISSN 1610-1634, E-ISSN 1610-1642, Vol. 0, no 7, p. 1985-1988Article in journal (Refereed)
    Abstract [en]

    We have grown GaN layers with a thickness up to 340 μm in an rf-heated vertical HVPE reactor with a bottom-fed design. The GaN layers were separated from the sapphire substrate by a LLO process. The free-standing GaN was investigated by HRXRD, AFM and low temperature CL. The FWHM values of the ω-scans are 96 and 129 arcsec for the (104) and (002) reflection, respectively, which indicates high crystalline quality. The c and a lattice parameters are determined as c = 0.51850 ± 0.00004 nm and a = 0.31890 ± 0.00004 nm, indicating stress free material. The etch pit density was estimated to be 1 × 107 cm−2. The used HVPE growth procedure together with the subsequent LLO are obviously capable to provide high-quality free-standing GaN material for further epitaxial overgrowth.

  • 165.
    Lartsev, A.
    et al.
    Chalmers, Sweden.
    Lara-Avila, S.
    Chalmers, Sweden.
    Danilov, A.
    Chalmers, Sweden.
    Kubatkin, S.
    Chalmers, Sweden.
    Tzalenchuk, A.
    National Phys Lab, England; University of London, England.
    Yakimova, Rositsa
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, Faculty of Science & Engineering. Graphensic AB, SE-58330 Linkoping, Sweden.
    A prototype of R-K/200 quantum Hall array resistance standard on epitaxial graphene2015In: Journal of Applied Physics, ISSN 0021-8979, E-ISSN 1089-7550, Vol. 118, no 4, p. 044506-Article in journal (Refereed)
    Abstract [en]

    Epitaxial graphene on silicon carbide is a promising material for the next generation of quantum Hall resistance standards. Single Hall bars made of graphene have already surpassed their state-of-the-art GaAs based counterparts as an R-K/2 (RK = h/e(2)) standard, showing at least the same precision and higher breakdown current density. Compared to single devices, quantum Hall arrays using parallel or series connection of multiple Hall bars can offer resistance values spanning several orders of magnitude and (in case of parallel connection) significantly larger measurement currents, but impose strict requirements on uniformity of the material. To evaluate the quality of the available material, we have fabricated arrays of 100 Hall bars connected in parallel on epitaxial graphene. One out of four devices has shown quantized resistance that matched the correct value of R-K/200 within the measurement precision of 10(-4) at magnetic fields between 7 and 9 T. The defective behaviour of other arrays is attributed mainly to non-uniform doping. This result confirms the acceptable quality of epitaxial graphene, pointing towards the feasibility of well above 90% yield of working Hall bars.

  • 166.
    Lartsev, Arseniy
    et al.
    Chalmers, Sweden.
    Yager, Tom
    Chalmers, Sweden.
    Bergsten, Tobias
    SP Technical Research Institute Sweden, Sweden.
    Tzalenchuk, Alexander
    National Phys Lab, England; University of London, England.
    Janssen, T. J. B. M.
    National Phys Lab, England.
    Yakimova, Rositsa
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, The Institute of Technology.
    Lara-Avila, Samuel
    Chalmers, Sweden.
    Kubatkin, Sergey
    Chalmers, Sweden.
    Tuning carrier density across Dirac point in epitaxial graphene on SiC by corona discharge2014In: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 105, no 6, p. 063106-Article in journal (Refereed)
    Abstract [en]

    We demonstrate reversible carrier density control across the Dirac point (Delta n similar to 10(13) cm(-2)) in epitaxial graphene on SiC (SiC/G) via high electrostatic potential gating with ions produced by corona discharge. The method is attractive for applications where graphene with a fixed carrier density is needed, such as quantum metrology, and more generally as a simple method of gating 2DEGs formed at semiconductor interfaces and in topological insulators.

  • 167.
    Lebedev, A.A.
    et al.
    Russian Academy of Sciences.
    Abramov, P.L.
    Russian Academy of Sciences.
    Bogdanova, E.V.
    Russian Academy of Sciences.
    Lebedev, S.P.
    Russian Academy of Sciences.
    Nelson, D.K.
    Russian Academy of Sciences.
    Oganesyan, G.A.
    Russian Academy of Sciences.
    Tregubova, A.S.
    Russian Academy of Sciences.
    Yakimova, Rositsa
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials.
    Highly doped p-type 3C-SiC on 6H-SiC substrates2008In: Semiconductor Science and Technology, ISSN 0268-1242, E-ISSN 1361-6641, Vol. 23, no 7Article in journal (Refereed)
    Abstract [en]

    Highly doped p-3C-SiC layers of good crystal perfection have been grown by sublimation epitaxy in vacuum. Analysis of the photoluminescence spectra and temperature dependence of the carrier concentration shows that at least two types of acceptor centers at ∼EV + 0.25 eV and at EV + 0.06-0.07 eV exist in the samples studied. A conclusion is reached that layers of this kind can be used as p-emitters in 3C-SiC devices. © 2008 IOP Publishing Ltd.

  • 168.
    Lebedev, A.A.
    et al.
    Ioffe Physicotechnical Institute, Russian Academy of Sciences, St. Petersburg 194021, Russian Federation.
    Kozlovski, V.V.
    St. Petersburg State Technical Univ., St. Petersburg 195251, Russian Federation.
    Strokan, N.B.
    Ioffe Physicotechnical Institute, Russian Academy of Sciences, St. Petersburg 194021, Russian Federation.
    Davydov, D.V.
    Ioffe Physicotechnical Institute, Russian Academy of Sciences, St. Petersburg 194021, Russian Federation.
    Ivanov, A.M.
    Ioffe Physicotechnical Institute, Russian Academy of Sciences, St. Petersburg 194021, Russian Federation.
    Strel'chuk, A.M.
    Ioffe Physicotechnical Institute, Russian Academy of Sciences, St. Petersburg 194021, Russian Federation.
    Yakimova, Rositsa
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Materials Science .
    Radiation hardness of wide-gap semiconductors (using the example of silicon carbide)2002In: Semiconductors (Woodbury, N.Y.), ISSN 1063-7826, E-ISSN 1090-6479, Vol. 36, no 11, p. 1270-1275Article in journal (Refereed)
    Abstract [en]

    Results obtained in studying the effect of ionizing radiation on epitaxial layers and devices based on silicon carbide (SiC) are considered. It is shown that, in investigations of wide-gap semiconductors (WGS), account should be taken of how the rate of removal of mobile charge carriers - the standard parameter in determining the radiation hardness of a material - depends on temperature. The use of data obtained only at room temperature may lead to an incorrect assessment of the radiation hardness of WGS. A conclusion is made that the WGS properties combine, on the one hand, high radiation hardness of high-temperature devices based on these semiconductors and, on the other, the possibility of effective radiation-induced doping (e.g., for obtaining semi-insulating local regions in a material at room temperature). © 2002 MAIK "Nauka/Interperiodica".

  • 169.
    Lebedev, A.A.
    et al.
    Ioffe Physicotechnical Institute, Russian Academy of Sciences, St. Petersburg, 194021, Russian Federation.
    Zelenin, V.V.
    Ioffe Physicotechnical Institute, Russian Academy of Sciences, St. Petersburg, 194021, Russian Federation.
    Abramov, P.L.
    Ioffe Physicotechnical Institute, Russian Academy of Sciences, St. Petersburg, 194021, Russian Federation.
    Lebedev, S.P.
    Ioffe Physicotechnical Institute, Russian Academy of Sciences, St. Petersburg, 194021, Russian Federation.
    Smirnov, A.N.
    Ioffe Physicotechnical Institute, Russian Academy of Sciences, St. Petersburg, 194021, Russian Federation.
    Sorokin, L.M.
    Ioffe Physicotechnical Institute, Russian Academy of Sciences, St. Petersburg, 194021, Russian Federation.
    Shcheglov, M.P.
    Ioffe Physicotechnical Institute, Russian Academy of Sciences, St. Petersburg, 194021, Russian Federation.
    Yakimova, Rositsa
    Linköping University, Department of Physics, Chemistry and Biology, Nanostructured Materials . Linköping University, The Institute of Technology.
    Studying 3C-SiC epilayers grown on the (0001)C face of 6H-SiC substrates2007In: Technical physics letters, ISSN 1063-7850, E-ISSN 1090-6533, Vol. 33, no 6, p. 524-526Article in journal (Refereed)
    Abstract [en]

    Epitaxial 3C-SiC films grown on the (0001)C face of 6H-SiC substrates by sublimation epitaxy in vacuum have been studied. The results of x-ray diffraction measurements show evidence of a rather high structural perfection of silicon carbide epilayers. The Raman spectroscopy data confirm that the 3C-SiC layer grows immediately on the 6H-SiC substrate without any transition layers. It is concluded that the structures under consideration are well suited for the investigation of a two-dimensional electron gas at the 3C-SiC/6C-SiC heterojunction. © Nauka/Interperiodica 2007.

  • 170.
    Lebedev, Alexander
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology.
    Davydov, DV
    Russian Acad Sci, AF Ioffe Physicotech Inst, St Petersburg 194021, Russia Linkoping Univ, S-58183 Linkoping, Sweden.
    Savkina, NS
    Russian Acad Sci, AF Ioffe Physicotech Inst, St Petersburg 194021, Russia Linkoping Univ, S-58183 Linkoping, Sweden.
    Tregubova, AS
    Russian Acad Sci, AF Ioffe Physicotech Inst, St Petersburg 194021, Russia Linkoping Univ, S-58183 Linkoping, Sweden.
    Shcheglov, MP
    Russian Acad Sci, AF Ioffe Physicotech Inst, St Petersburg 194021, Russia Linkoping Univ, S-58183 Linkoping, Sweden.
    Yakimova, Rositsa
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Materials Science .
    Syväjärvi, Mikael
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Materials Science .
    Janzén, Erik
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Materials Science .
    Structural defects and deep-level centers in 4H-SiC epilayers grown by sublimational epitaxy in vacuum2000In: Semiconductors (Woodbury, N.Y.), ISSN 1063-7826, E-ISSN 1090-6479, Vol. 34, no 10, p. 1133-1136Article in journal (Refereed)
    Abstract [en]

    The parameters of deep-level centers in lightly doped 4H-SiC epilayers grown by sublimational epitaxy and CVD were investigated. Two deep-level centers with activation energies E-c - 0.18 eV and E-c - 0.65 eV (Z1 center) were observed and tentatively identified with structural defects of the SiC crystal lattice. The Z1 center concentration is shown to fall with decreasing uncompensated donor concentration N-d - N-a in the layers. For the same N-d - N-a, the Z1 center concentration is lower in layers with a higher dislocation density. (C) 2000 MAIK "Nauka/Interperiodica".

  • 171.
    Lebedev, Alexander
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology.
    Kozlovski, VV
    Strokan, NB
    Davydov, DV
    Ivanov, AM
    Strel'chuk, AM
    Yakimova, Rositsa
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials.
    Radiation hardness of silicon carbide2003In: Materials Science Forum, Vols. 433-436, 2003, Vol. 433-4, p. 957-960Conference paper (Refereed)
    Abstract [en]

    The aim of this study was an estimation of the radiation hardness of silicon carbide and devices on its base. By using data, obtained by the authors, and literature data, it was possible to calculate carrier removal rate in SiC, irradiated by different charge participles, radiation defects (RD) introduction rate and generation constant of deeper RD. The obtained results were compared with known values of this parameters for Si. Results of comparison show, that during calculation of above parameters for SiC (or other wide-bandgap semiconductors (WBS), it is necessary to take into account their temperature dependence. Commonly, this comparison shows, that SiC is perspective material for developing radiation resistive devices, especially if they must work at high temperatures.

  • 172.
    Lebedev, Alexander
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology.
    Zelenin, V.V.
    Abramov, P.L.
    Bogdanova, E.V.
    Lebedev, S.P.
    Nelson, D.K.
    Razbirin, B.S.
    Scheglov, M.P.
    Tregubova, A.S.
    Syväjärvi, Mikael
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Materials Science .
    Yakimova, Rositsa
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Materials Science .
    Growth and Study of Thick 3C-SiC Epitaxial Layers Produced by Epitaxy on 6H-SiC Substrates2007In: ECSCRM 2006,2006, Materials Science Forum, vol. 556.557: Trans Tech Publications , 2007, p. 175-Conference paper (Refereed)
  • 173.
    Lebedev, Alexander
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology.
    Zelenin, V.V.
    Abramov, P.L.
    Bogdanova, E.V.
    Lebedev, S.P.
    Nel¿son, D.K.
    Razbirin, B.S.
    Shcheglov, M.P.
    Tregubova, A.S.
    Syväjärvi, Mikael
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Materials Science .
    Yakimova, Rositsa
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Materials Science .
    A study of thick 3C-SiC epitaxial layers grown on 6H-SiC substrates by sublimation epitaxy in vacuum2007In: Semiconductors (Woodbury, N.Y.), ISSN 1063-7826, E-ISSN 1090-6479, Vol. 41, no 3, p. 263-265Article in journal (Refereed)
    Abstract [en]

    3C-SiC epitaxial layers with a thickness of up to 100 μm were grown on 6H-SiC hexagonal substrates by sublimation epitaxy in vacuum. The n-type epitaxial layers with the area in the range 0.3-0.5 cm2 and uncompensated donor concentration N d - N a ∼ (10 17-1018) cm-3 were produced at maximum growth rates of up to 200 μm/h. An X-ray analysis demonstrated that the epitaxial layers are composed of the 3C-SiC polytype, without inclusions of other polytypes. The photoluminescence (PL) spectrum of the layers was found to be dominated by the donor-acceptor (Al-N) recombination band peaked at hv ≈ 2.12 eV. The PL spectrum measured at 6 K was analyzed in detail. It is concluded that the epitaxial layers obtained can serve as substrates for 3C-SiC-based electronic devices. © Nauka/Interperiodica 2007.

  • 174. Lebedev, S.P.
    et al.
    Lebedev, A.A.
    Abramov, P.L.
    Bogdanova, E.V.
    Nel¿son, D.K.
    Oganesyan, G.A.
    Tregubova, A.S.
    Yakimova, Rositsa
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials.
    P-type 3C-SiC Grown by Sublimation Epitaxy on 6H-SiC Substrates2009In: ECSCRM2008,2008, Materials Science Forum Vols. 615-617: Trans Tech Publications , 2009, p. 177-180Conference paper (Refereed)
    Abstract [en]

    Highly doped p-3C-SiC layers of good crystal perfection have been grown by sublimation epitaxy in vacuum. Analysis of the photoluminescence (PL) spectra and temperature dependence of the carrier concentration shows that at least two types of acceptor centers at ~EV + 0.25 eV and at EV + 0.06-0.07 eV exist in the samples studied. A conclusion is made that layers of this kind can be used as p-emitters in 3C-SiC devices.

  • 175.
    Li, Fan
    et al.
    University of Warwick, Coventry, United Kingdom.
    Jokubavicius, Valdas
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, Faculty of Science & Engineering.
    Jennings, Michael
    University of Warwick, Coventry, United Kingdom.
    Yakimova, Rositsa
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, Faculty of Science & Engineering.
    Tomas, Amador Perez
    ICN2, CSIC and the Barcelona Institute of Science and Technology, Bellaterra, Barcelona, Spain.
    Russell, Stephen
    University of Warwick, Coventry, United Kingdom.
    Sharma, Yogesh
    University of Warwick, Coventry, United Kingdom.
    Roccaforte, Fabrizio
    CNR-IMM, sezione di Catania, Catania, Italy.
    Mawby, Philip
    University of Warwick, Coventry, United Kingdom.
    La Via, Francesco
    CNR-IMM, sezione di Catania, Catania, Italy.
    Electrical Characterisation of Thick 3C-SiC Layers Grown on Off-Axis 4H-SiC Substrates2019In: Materials Science Forum, ISSN 0255-5476, E-ISSN 1662-9752, Vol. 963, p. 353-356Article in journal (Refereed)
    Abstract [en]

    300 μm thick 3C-SiC epilayer was grown on off-axis 4H-SiC(0001) substrate with a high growth rate of 1 mm/hour. Dry oxidation, wet oxidation and N2O anneal were applied to fabricate lateral MOS capacitors on these 3C-SiC layers. MOS interface obtained by N2O anneal has the lowest interface trap density of 3~4x1011 eV-1cm-2. Although all MOS capacitors still have positive net charges at the MOS interface, the wet oxidised sample has the lowest effective charge density of ~9.17x1011 cm-2.

  • 176.
    Linnarsson, MK
    et al.
    Royal Inst Technol, SE-16440 Kista, Sweden Linkoping Univ, Dept Phys & Measurement Technol, SE-58183 Linkoping, Sweden ABB Corp Res, SE-16440 Kista, Sweden ACREO AB, SE-16440 Kista, Sweden Univ Oslo, Dept Phys, NO-0316 Oslo, Norway.
    Persson, Per
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics.
    Bleichner, H
    Royal Inst Technol, SE-16440 Kista, Sweden Linkoping Univ, Dept Phys & Measurement Technol, SE-58183 Linkoping, Sweden ABB Corp Res, SE-16440 Kista, Sweden ACREO AB, SE-16440 Kista, Sweden Univ Oslo, Dept Phys, NO-0316 Oslo, Norway.
    Janson, MS
    Zimmermann, U
    Royal Inst Technol, SE-16440 Kista, Sweden Linkoping Univ, Dept Phys & Measurement Technol, SE-58183 Linkoping, Sweden ABB Corp Res, SE-16440 Kista, Sweden ACREO AB, SE-16440 Kista, Sweden Univ Oslo, Dept Phys, NO-0316 Oslo, Norway.
    Andersson, H
    Karlsson, S
    Yakimova, Rositsa
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials.
    Hultman, Lars
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics.
    Svensson, BG
    Precipitate formation in heavily Al-doped 4H-SiC layers2001In: Materials Science Forum, Vols. 353-356, 2001, Vol. 353-3, p. 583-586Conference paper (Refereed)
    Abstract [en]

    Epitaxially grown 4H-SiC structures with several heavily Al doped layers were used. The samples were annealed in Ar atmosphere in a RF-heated furnace between 1500 and 2900 degreesC for 0.5 to 3h. Secondary ion mass spectrometry (SIMS) was used to measure the aluminum concentration versus,depth as well as the lateral distribution (ion images). Transmission electron microscopy (TEM) was employed to study the crystallinity and determine phase composition after heat treatment. A solubility limit of 2x10(20) Al/cm(3) at 2000 degreesC is extracted. Ion images of the lateral Al distribution reveal a pronounced dependence on the Al content. Precipitate formation occurs after heat treatment at 1700 - 2000 degreesC when the Al concentration exceeds 2x10(20) cm(-3) and energy-filtered TEM (EFTEM) shows that the precipitates contain Al.

  • 177.
    Lloyd Spetz, Anita
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Buchholt, Kristina
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Lutic, Doina
    Lunds universitet.
    Strand, M
    Växjö universitet.
    Käll, Per-Olov
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Physical Chemistry .
    Sanati, Mehri
    Lunds universitet.
    Yakimova, Rositsa
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Materials Science .
    Multifunctional chemical sensors based on wide band gap materials2007In: MRS Spring Meeting,2007, 2007Conference paper (Refereed)
    Abstract [en]

       

  • 178.
    Lloyd Spetz, Anita
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Eriksson, Jens
    Ehrler, S
    Khranovskyy, Volodymyr
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Materials Science .
    Yakimova, Rositsa
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Materials Science .
    Käll, Per-Olov
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Physical Chemistry .
    Gas sensors based on ZnO nanopraticels or film: A comparison2008In: IMCS 12,2008, 2008, p. 89-Conference paper (Refereed)
    Abstract [en]

       

  • 179.
    Lloyd Spetz, Anita
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Pearce, Ruth
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Hedin, Linnea
    Linköping University, Department of Physics, Chemistry and Biology, Chemistry. Linköping University, The Institute of Technology.
    Khranovskyy, Volodymyr
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, The Institute of Technology.
    Söderlind, Fredrik
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Physics. Linköping University, The Institute of Technology.
    Käll, Per-Olov
    Linköping University, Department of Physics, Chemistry and Biology, Physical Chemistry. Linköping University, The Institute of Technology.
    Yakimova, Rositsa
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, The Institute of Technology.
    Uvdal, Kajsa
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    New transducer material concepts for biosensors and surface functionalization2009In: Smart Sensors, Actuators,and MEMS IV / [ed] Ulrich Schmid, Carles Cané, Herbert Shea, Bellingham, WA United States: SPIE - International Society for Optical Engineering, 2009, Vol. 7362, p. 736206-Conference paper (Refereed)
    Abstract [en]

    Wide bandgap materials like SiC, ZnO, AlN form a strong platform as transducers for biosensors realized as e.g. ISFET (ion selective field effect transistor) devices or resonators. We have taken two main steps towards a multifunctional biosensor transducer. First we have successfully functionalized ZnO and SiC surfaces with e.g. APTES. For example ZnO is interesting since it may be functionalized with biomolecules without any oxidation of the surface and several sensing principles are possible. Second, ISFET devises with a porous metal gate as a semi-reference electrode are being developed. Nitric oxide, NO, is a gas which participates in the metabolism. Resistivity changes in Ga doped ZnO was demonstrated as promising for NO sensing also in humid atmosphere, in order to simulate breath.

  • 180.
    Lloyd-Spets, Anita
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Nakagomi, S.
    School of Science and Engineering, Ishinomaki Senshu University, Ishinomaki, Miyagi, Japan.
    Wingbrant, Helena
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Andersson, Mike
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Salomonsson, Anette
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Roy, S.
    Wingqvist, G.
    Ångström Laboratory, Uppsala University, Uppsala, Sweden.
    Katardjiev, I.
    Ångström Laboratory, Uppsala University, Uppsala, Sweden.
    Eickhoff, M.
    Walter Schottky Institut, Technishce Universität München, Am. Coulombwall, Garching, Germany.
    Uvdal, Kajsa
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Sensor Science and Molecular Physics .
    Yakimova, Rositsa
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Materials Science .
    New materials for chemical and biosensors2006In: Materials and Manufacturing Processes, ISSN 1042-6914, E-ISSN 1532-2475, Vol. 21, no 3, p. 253-256Article in journal (Refereed)
    Abstract [en]

    Wide band gap materials such as SiC, AlN, GaN, ZnO, and diamond have excellent properties such as high operation temperature when used as field effect devices and a high resonating frequency of the substrate materials used in piezoelectric resonator devices. Integration of FET and resonating sensors on the same chip enables powerful miniaturized devices, which can deliver increased information about a gas mixture or complex liquid. Examples of sensor devices based on different wide band gap materials will be given.

  • 181.
    Lloyd-Spets, Anita
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Petoral, Rodrigo Jr
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Sensor Science and Molecular Physics .
    Uvdal, Kajsa
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Sensor Science and Molecular Physics .
    Vahlberg, Cecilia
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Sensor Science and Molecular Physics .
    Yakimova, Rositsa
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Materials Science .
    Steinhoff, G.
    Baur, B.
    Wassner, T.
    Eickhoff, M.
    Chemical functionalization of GaN and ZnO surfaces2006In: Proc. IMCS11,2006, 2006Conference paper (Refereed)
  • 182.
    Lloyd-Spets, Anita
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Petoral, Rodrigo Jr
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Sensor Science and Molecular Physics .
    Yazdi, Gholam Reza
    IFM .
    Vahlberg, Cecilia
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Sensor Science and Molecular Physics .
    Syväjärvi, Mikael
    IFM .
    Uvdal, Kajsa
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Sensor Science and Molecular Physics .
    Yakimova, Rositsa
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Materials Science .
    Surface functioanlization of SiC for biosensor applications2006In: Proc. ECSCRM 2006,2006, 2006Conference paper (Refereed)
  • 183.
    Lloyd-Spets, Anita
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Steinhoff, Georg
    Technische Universität München, Germany.
    Khranovsky, Volodymyr
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials.
    Andersson, Mike
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Buchholt, Kristina
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Eickhoff, M.
    Technische Universität München, Germany.
    Yakimova, Rositsa
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, The Institute of Technology.
    Multisensing by Gas Sensors2006In: Proceedings Eurosensors XX: 20th anniversary, Göteborg, Sweden, 17 - 20 September 2006,, 2006, article id T3A-KNConference paper (Refereed)
  • 184.
    Lloyd-Spets, Anita
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Steinhoff, Georg
    Petoral, Rodrigo Jr
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Sensor Science and Molecular Physics .
    Uvdal, Kajsa
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Sensor Science and Molecular Physics .
    Eickhoff, Martin
    Yakimova, Rositsa
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Materials Science .
    New Materials for Multifunctional Chemical- and Biosensors2006In: MST06 Chemically Active Ceramic Nano-Particles and Nano-Structures,2006, 2006Conference paper (Refereed)
    Abstract [en]

      

  • 185.
    Lloyd-Spets, Anita
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Uvdal, Kajsa
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Sensor Science and Molecular Physics .
    Eickhoff, Martin
    Walter Schottky Inst. München Univresity.
    Katardjiev, Ilia
    Uppsala universitet.
    Yakimova, Rositsa
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Materials Science .
    Wide band-gap materials for chemical and biosensors2005In: International Symposium for Advanced Sensor Technologies,2005, 2005, p. 25-30Conference paper (Refereed)
  • 186.
    Maassen, Thomas
    et al.
    University of Groningen.
    van den Berg, J Jasper
    University of Groningen.
    IJbema, Natasja
    University of Groningen.
    Fromm, Felix
    University of Erlangen Nurnberg.
    Seyller, Thomas
    University of Erlangen Nurnberg.
    Yakimova, Rositsa
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, The Institute of Technology.
    van Wees, Bart J
    University of Groningen.
    Long Spin Relaxation Times in Wafer Scale Epitaxial Graphene on SiC(0001)2012In: Nano letters (Print), ISSN 1530-6984, E-ISSN 1530-6992, Vol. 12, no 3, p. 1498-1502Article in journal (Refereed)
    Abstract [en]

    We developed an easy, upscalable process to prepare lateral spin-valve devices on epitaxially grown monolayer graphene on SiC(0001) and perform nonlocal spin transport measurements. We observe the longest spin relaxation times tau(s) in monolayer graphene, while the spin diffusion coefficient D-s is strongly reduced compared to typical results on exfoliated graphene. The increase of tau(s) is probably related to the changed substrate, while the cause for the small value of D-s remains an open question.

  • 187.
    Mammadov, Samir
    et al.
    Technical University of Chemnitz, Germany.
    Ristein, Juergen
    University of Erlangen Nurnberg, Germany.
    Koch, Roland J.
    Technical University of Chemnitz, Germany.
    Ostler, Markus
    Technical University of Chemnitz, Germany.
    Raidel, Christian
    Technical University of Chemnitz, Germany.
    Wanke, Martina
    Technical University of Chemnitz, Germany.
    Vasiliauskas, Remigijus
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, The Institute of Technology.
    Yakimova, Rositsa
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, Faculty of Science & Engineering.
    Seyller, Thomas
    Technical University of Chemnitz, Germany.
    Polarization doping of graphene on silicon carbide2014In: 2D MATERIALS, ISSN 2053-1583, Vol. 1, no 3, p. 035003-Article in journal (Refereed)
    Abstract [en]

    The doping of quasi-freestanding graphene (QFG) on H-terminated, Si-face 6H-, 4H-, and 3C-SiC is studied by angle-resolved photoelectron spectroscopy close to the Dirac point. Using semi-insulating as well as n-type doped substrates we shed light on the contributions to the charge carrier density in QFG caused by (i) the spontaneous polarization of the substrate, and (ii) the band alignment between the substrate and the graphene layer. In this way we provide quantitative support for the previously suggested model of polarization doping of graphene on SiC (Ristein et al 2012 Phys. Rev. Lett. 108 246104).

  • 188.
    Mazzola, Federico
    et al.
    Norwegian University of Science and Technology NTNU, Norway .
    Wells, Justin W.
    Norwegian University of Science and Technology NTNU, Norway .
    Yakimova, Rositsa
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, The Institute of Technology.
    Ulstrup, Soren
    Aarhus University, Denmark .
    Miwa, Jill A.
    Aarhus University, Denmark .
    Balog, Richard
    Aarhus University, Denmark .
    Bianchi, Marco
    Aarhus University, Denmark .
    Leandersson, Mats
    Lund University, Sweden .
    Adell, Johan
    Lund University, Sweden .
    Hofmann, Philip
    Aarhus University, Denmark .
    Balasubramanian, T
    Lund University, Sweden .
    Kinks in the σ Band of Graphene Induced by Electron-Phonon Coupling2013In: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 111, no 21, p. 216806-Article in journal (Refereed)
    Abstract [en]

    Angle-resolved photoemission spectroscopy reveals pronounced kinks in the dispersion of the σ band of graphene. Such kinks are usually caused by the combination of a strong electron-boson interaction and the cutoff in the Fermi-Dirac distribution. They are therefore not expected for the σ band of graphene that has a binding energy of more than ≈3.5  eV. We argue that the observed kinks are indeed caused by the electron-phonon interaction, but the role of the Fermi-Dirac distribution cutoff is assumed by a cutoff in the density of σ states. The existence of the effect suggests a very weak coupling of holes in the σ band not only to the π electrons of graphene but also to the substrate electronic states. This is confirmed by the presence of such kinks for graphene on several different substrates that all show a strong coupling constant of λ≈1.

  • 189. Mikelsen, M.
    et al.
    Grossner, U.
    Bleka, J.
    Monakhov, E.
    Svensson, B.
    Yakimova, Rositsa
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials.
    Henry, Anne
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials.
    Janzén, Erik
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials.
    Lebedev, A.
    Carrier Removal in Electron Irradiated 4H and 6H SiC2009In: Materials Science Forum, Vols. 600-603, Trans Tech Publications , 2009, , p. 425-428p. 425-428Conference paper (Refereed)
    Abstract [en]

    A strong reduction of the free carrier concentration has been observed in both 4H and 6H n-type SiC as a result of MeV-electron irradiation. Samples irradiated with a sufficiently high dose experience complete compensation of carriers. Irradiation with even higher doses reveals the same result, i.e. no conversion to p-type which occurs in silicon irradiated with high doses has been found. The dose required for complete loss of carrier response is higher for 6H than 4H material. Furthermore, the free carrier concentration depends on both measurement temperature and frequency and recovers after annealing. The results strongly suggest that deep acceptor levels in the upper half of the band gap are the main cause for the removal of free carriers rather than deactivation of the nitrogen donors as found in ion-irradiated samples, which is in agreement with previous findings on proton-irradiated 4H- and 6H-SiC[8]. © (2009) Trans Tech Publications, Switzerland.

  • 190. Mikelsen, M.
    et al.
    Monakhov, E.V.
    Bleka, J.H.
    Yakimova, Rositsa
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials.
    Henry, Anne
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials.
    Janzén, Erik
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials.
    Lebedev, Alexander
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology.
    Svensson, B.G.
    Irradiation Induced Carrier Loss in 4H and 6H SiC2006In: Materials Science Forum, Vols. 556-557, 2006Conference paper (Other academic)
  • 191.
    Mikoushkin, V. M.
    et al.
    Ioffe Institute, Russia.
    Shnitov, V. V.
    Ioffe Institute, Russia.
    Lebedev, A. A.
    Ioffe Institute, Russia; University of ITMO, Russia.
    Lebedev, S. P.
    Ioffe Institute, Russia; University of ITMO, Russia.
    Nikonov, S. Yu.
    Ioffe Institute, Russia.
    Vilkou, O. Yu.
    Technical University of Dresden, Germany; St Petersburg State University, Russia.
    Iakimou, T.
    Ioffe Institute, 194021 St. Petersburg, Russia.
    Yakimova, Rositsa
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, The Institute of Technology.
    Size confinement effect in graphene grown on 6H-SiC (0001) substrate2015In: Carbon, ISSN 0008-6223, E-ISSN 1873-3891, Vol. 86, p. 139-145Article in journal (Refereed)
    Abstract [en]

    We have observed the energy structure in the density of occupied states of graphene grown on n-type 6H-SiC (0001). The structure revealed with photoelectron spectroscopy is described by creation of the quantum well states whose number and the energy position (E-1 = 0.3 eV, E-2 = 1.2 eV, E-3 = 2.6 eV) coincide with the calculated ones for deep (V = 2.9 eV) and narrow (d = 2.15 angstrom) quantum well formed by potential relief of the valence bands in the structure graphene/n-SiC. We believe that the quantum well states should be formed also in graphene on dielectric and in suspended graphene. (C) 2015 Elsevier Ltd. All rights reserved.

  • 192.
    Nachawaty, A.
    et al.
    Univ Montpellier, France; Lebanese Univ, Lebanon.
    Yang, M.
    Univ Toulouse, France.
    Nanot, S.
    Univ Montpellier, France.
    Kazazis, D.
    Univ Paris Saclay, France; Paul Scherrer Inst, Switzerland.
    Yakimova, Rositsa
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, Faculty of Science & Engineering.
    Escoffier, W.
    Univ Toulouse, France.
    Jouault, B.
    Univ Montpellier, France.
    Large nonlocality in macroscopic Hall bars made of epitaxial graphene2018In: Physical Review B, ISSN 2469-9950, E-ISSN 2469-9969, Vol. 98, no 4, article id 045403Article in journal (Refereed)
    Abstract [en]

    We report on nonlocal transport in large-scale epitaxial graphene on silicon carbide under an applied external magnetic field. The nonlocality is related to the emergence of the quantum Hall regime and persists up to the millimeter scale. The nonlocal resistance reaches values comparable to the local (Hall and longitudinal) resistances. At moderate magnetic fields, it is almost independent on the in-plane component of the magnetic field, which suggests that spin currents are not at play. The nonlocality cannot be explained by thermoelectric effects without assuming extraordinary large Nernst and Ettingshausen coefficients. A model based on counterpropagating edge states backscattered by the bulk reproduces quite well the experimental data.

  • 193.
    Nakagomi, S
    et al.
    Ishinomaki Senshu Univ, Sch Engn, Ishinomaki 9868580, Japan Linkoping Univ, Div Appl Phys, SE-58183 Linkoping, Sweden SSENCE, SE-58183 Linkoping, Sweden Linkoping Univ, Dept Phys & Measurement Technol, SE-58183 Linkoping, Sweden.
    Shinobu, H
    Ishinomaki Senshu Univ, Sch Engn, Ishinomaki 9868580, Japan Linkoping Univ, Div Appl Phys, SE-58183 Linkoping, Sweden SSENCE, SE-58183 Linkoping, Sweden Linkoping Univ, Dept Phys & Measurement Technol, SE-58183 Linkoping, Sweden.
    Unéus, Lars
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Lundström, Ingemar
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Ekedahl, Lars-Gunnar
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology.
    Yakimova, Rositsa
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials.
    Syväjärvi, Mikael
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials.
    Henry, Anne
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials.
    Janzén, Erik
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials.
    Lloyd-Spets, Anita
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Influence of epitaxial layer on SiC Schottky diode gas sensors operated under high-temperature conditions2002In: Materials Science Forum, Vols. 389-393, 2002, Vol. 389-3, p. 1423-1426Conference paper (Refereed)
    Abstract [en]

    Schottky diode gas sensors were fabricated on top of the epitaxial layer grown by three different methods, purchased from Cree Research Inc., by hot wall CVD, or by sublimation at a high growth rate. The epitaxial layers have different thickness and doping. The current-voltage characteristics of the gas sensors were compared in different gas ambient during operation in the high temperature region. The temperature dependence of the series resistance of the diodes revealed two types of carrier scattering mechanisms, impurity scattering for the sublimation epitaxial layer at 300-400degreesC and at 400-600degreesC, lattice scattering for all diodes. The ideality factor of the diode fabricated on the Cree substrate is higher than others. The higher ideality factor gives rise to a larger forward voltage change for a change in gas ambient. The amount of change in barrier height caused by a change in the ambient gas is almost the same for the three types of diodes. The value of the barrier height of the diode grown by the sublimation method is lower than for the others, which gives a higher reverse saturation current at temperatures above 400degreesC. The largest saturation current also shows the largest current change when switching between different gas atmospheres.

  • 194.
    Neimontas, K.
    et al.
    Vilnius University.
    Jarasiunas, K.
    Vilnius University.
    Yakimova, Rositsa
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, The Institute of Technology.
    Syväjärvi, Mikael
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, The Institute of Technology.
    Ferro, G.
    UCB Lyon I.
    Characterization of electronic properties of different SiC polytypes by all-optical means2009In: Materials Science Forum, Vols. 600-603, 2009, Vol. 600-603, p. 509-512Conference paper (Refereed)
    Abstract [en]

    We applied a picosecond transient grating technique for studies of nonequilibrium carrier dynamics in differently grown or doped SiC polytypes. Optical carrier injection in 4H-SiC at two different wavelengths (266 and 355 nm) allowed us to vary the depth of the photoexcited region and determine photoelectric parameters of high density (from ~1016 to ~1019 cm-3) carrier plasma in the temperature range 10-300 K. A strong decrease of carrier lifetime with increasing nonequlibrium carrier density was found in 4H-SiC samples at 300 K and fitted by bimolecular recombination with coefficient B = 3 � 10-11 cm3 s-1. In 3C-SiC epilayers, the opposite tendency was observed over a wide temperature range and attributed to recharging of defect states.

  • 195. Neimontas, K.
    et al.
    Malinauskas, T.
    Aleksiejunas, R.
    Yakimova, Rositsa
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Materials Science .
    Jarasiunas, K.
    Temperature-dependent nonequilibrium carrier dynamics in epitaxial and bulk 4H-SiC2006In: Lithuanian journal of physics, ISSN 1392-1932, Vol. 46, p. 199-204Article in journal (Refereed)
  • 196.
    Nguyen, Son Tien
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Materials Science .
    Ivanov, Ivan Gueorguiev
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Materials Science .
    Kuznetsov, A.
    Svensson, B.G.
    Zhao, Qing Xiang
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    Willander, Magnus
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    Morishita, N.
    Ohshima, T.
    Itoh, H.
    Isoya, J.
    Janzén, Erik
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Materials Science .
    Yakimova, Rositsa
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Materials Science .
    Recombination centers in as-grown and electron-irradiated ZnO substrates2007In: Journal of Applied Physics, ISSN 0021-8979, E-ISSN 1089-7550, Vol. 102, no 9Article in journal (Refereed)
    Abstract [en]

    Optical detection of magnetic resonance (ODMR) was used to study defects in ZnO substrates irradiated with 3 MeV electrons at room temperature. The Zn vacancy and some other ODMR centers were detected. Among these, the Zn vacancy and two other centers, labeled as LU3 and LU4, were also commonly observed in different types of as-grown ZnO substrates. The LU3 and LU4 are related to intrinsic defects and act as dominating recombination centers in irradiated and as-grown ZnO. © 2007 American Institute of Physics.

  • 197.
    Nguyen, Son Tien
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials.
    Ivanov, Ivan Gueorguiev
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials.
    Kuznetsov, A.
    Svensson, B.G.
    Zhao, Q.X.
    Willander, Magnus
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    Morishita, M.N.
    Ohshirma, T.
    Itoh, H.
    Janzén, Erik
    Linköping University, Department of Physics, Chemistry and Biology, Nanostructured Materials . Linköping University, The Institute of Technology.
    Yakimova, Rositsa
    Linköping University, Department of Physics, Chemistry and Biology, Nanostructured Materials . Linköping University, The Institute of Technology.
    Common point defects in as-grown ZnO substrates studied by optical detection of magnetic resonance2008In: Journal of Crystal Growth, Vol. 310, 2008, Vol. 310, no 5, p. 1006-1009Conference paper (Refereed)
    Abstract [en]

    Defects in as-grown commercial zinc oxide (ZnO) substrates were studied by photoluminescence and optical detection of magnetic resonance (ODMR). In addition to the Zn vacancy and shallow donor centers, we observed several ODMR centers with spin S=1/2, labeled LU1-LU4. Among these, the axial LU3 and non-axial LU4 centers were detected in all studied samples. The ODMR signals of LU3/LU4 were found to be drastically increased after electron irradiation. The preliminary result indicates that these common ODMR centers in as-grown ZnO are related to intrinsic defects. © 2007 Elsevier B.V. All rights reserved.

  • 198.
    Nguyen, Son Tien
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, The Institute of Technology.
    Ivanov, Ivan Gueorguiev
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, The Institute of Technology.
    Kuznetsov, A. Yu.
    Department of Physics, Center for Materials Science and Technology, University of Oslo, Oslo, Norway.
    Svensson, B.G.
    Department of Physics, Center for Materials Science and Technology, University of Oslo, Oslo, Norway.
    Zhao, Qing Xiang
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Willander, Magnus
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Morishita, M.N.
    Japan Atomic Energy Agency, Takasaki, Gunma, Japan.
    Ohshima, T.
    Japan Atomic Energy Agency, Takasaki, Gunma, Japan.
    Itoh, H.
    Japan Atomic Energy Agency, Takasaki, Gunma, Japan.
    Isoya, J.
    University of Tsukuba, Tsukuba, Japan.
    Janzén, Erik
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, The Institute of Technology.
    Yakimova, Rositsa
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, The Institute of Technology.
    Magnetic resonance studies of defects in electron-irradiated ZnO substrates2007In: Physica. B, Condensed matter, ISSN 0921-4526, E-ISSN 1873-2135, Vol. 401-402, p. 507-510Article in journal (Refereed)
    Abstract [en]

    Optical detection of magnetic resonance (ODMR) was used to study defects in electron-irradiated ZnO substrates. In addition to the shallow donor and the Zn vacancy, several ODMR centers with an effective electron spin were detected. Among these, the axial LU3 and non-axial LU4 centers are shown to be dominating recombination centers. The annealing behavior of radiation-induced defects was studied and possible defect models are discussed.

  • 199.
    Nicotra, G.
    et al.
    CNR, Italy.
    Deretzis, I.
    CNR, Italy.
    Scuderi, M.
    CNR, Italy.
    Spinella, C.
    CNR, Italy.
    Longo, P.
    Gatan Inc, CA 94588 USA.
    Yakimova, Rositsa
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, The Institute of Technology.
    Giannazzo, F.
    CNR, Italy.
    La Magna, A.
    CNR, Italy.
    Interface disorder probed at the atomic scale for graphene grown on the C face of SiC2015In: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 91, no 15, p. 155411-Article in journal (Refereed)
    Abstract [en]

    We use aberration-corrected scanning transmission electron microscopy, electron energy-loss spectroscopy, atomic force microscopy, and the density functional theory to study the structural and electronic characteristics of graphene grown on the C face of SiC. We show that for high growth temperatures the graphene/SiC(000 (1) over bar) interface is dominated by a thin amorphous film which strongly suppresses the epitaxy of graphene on the SiC substrate. This film maintains an almost fixed thickness regardless of the number of the overlying graphene layers, while its chemical signature shows the presence of C, Si, and O. Structurally, the amorphous area is inhomogeneous, as its Si concentration gradually decreases while approaching the first graphene layer, which is purely sp(2) hybridized. Ab initio calculations show that the evaporation process and the creation of Si vacancies on the C face of SiC strongly enhance the surface disorder and designate defect areas as preferential sublimation sites. Based on these features, we discuss differences and similarities between the C-only buffer layer that forms on the Si face of SiC and the thicker C-Si-O amorphous film of the C face.

  • 200.
    Nordell, N.
    et al.
    Department of Microelectronics and Information Technology, Kungliga Tekniska Högskolan, Electrum 229, SE-164 40 Kista, Sweden.
    Bowallius, O.
    Department of Microelectronics and Information Technology, Kungliga Tekniska Högskolan, Electrum 229, SE-164 40 Kista, Sweden.
    Anand, S.
    Department of Microelectronics and Information Technology, Kungliga Tekniska Högskolan, Electrum 229, SE-164 40 Kista, Sweden.
    Kakanakova-Georgieva, Anelia
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials.
    Yakimova, Rositsa
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials.
    Madsen, L.D.
    Karlsson, S.
    ACREO, Electrum 236, SE-164 40 Kista, Sweden.
    Konstantinov, A.O.
    ACREO, Electrum 236, SE-164 40 Kista, Sweden.
    Polytype homogeneity and doping distribution in homoepitaxial 4H SiC grown on nonplanar substrates2002In: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 80, no 10, p. 1755-Article in journal (Refereed)
    Abstract [en]

    [No abstract available]

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