Dickerhof, M., Parusel, A., Bittner, K., Anson, S., Kautt, M., Gengenbach, U., ...
MikroSystemTechnik Kongress 2009, Berlin, 12.-14.Oktober 2009
Anson, S., Bittner, K., Dickerhof, M., Gengenbach, U., Kaufmann, U., Kautt, M., ...
4M/ICOMM 2009 : The Global Conf.on Micro Manufacture, Karlsruhe, September 23- 25, 2009
Kunzer, M., Maier, M., Köhler, K., Kaufmann, U., Wagner, J.
Temperature and excitation power dependent photoluminescence spectroscopy on GaInN UV-violet LED structures allows to separate the influence of the quantum confined stark effect (QCSE) from carrier...
Enhancement of (AlGaIn)N near-UV LED efficiency using freestanding GaN substrate (2008)
Maier, M., Köhler, K., Kunzer, M., Wiegert, J., Liu, S., Kaufmann, U., ...
The effect of freestanding GaN-substrates with low defect density (DD) on the electroluminescence (EL) characteristics of near UV-LEDs has been investigated. Three series of LED-structures with...
Free form fabrication of 3D-ceramic parts with inkjet-printing. (2008)
Kaufmann, U., Harrysson, U., Johander, P., Bauer, W.
Industrial Ceramics, 28(2008) Nr.1, S.45-51
Globe MST - a European perspective on the global future of microsystems. (2008)
Anson, S., Bittner, K., Dickerhof, M., Gengenbach, U., Kaufmann, U., Kautt, M., ...
Commercialization of Micro and Nano Systems Conf. (COMS 2008), Puerto Vallarta, MEX, August 31 - September 4, 2008
GLOBE MST - metastudy on the state of the art in microsystem technology. (2008)
Dickerhof, M., Anson, S., Bittner, K., Kautt, M., Kaufmann, U., Schmidt, A.
mst news, (2008) Nr.5, S.24-26
Ceramic micro heater technology for gas sensors. (2008)
Moldovan, C., Nedelcu, O., Johander, P., Goenaga, I., Gomez, D., Petkov, P., ...
Romanian Journal of Information Science and Technology, 10(2007) S.43-52
Periodic parabolic problems with nonlinearities indefinite in sign (2007)
Let $\Omega\subset\mathbb{R}^{N}$ be a smooth bounded domain. We give sufficient conditions (which are also necessary in many cases) on two nonnegative functions $a$, $b$ that are possibly...
Kunzer, M., Baeumler, M., Köhler, K., Kaufmann, U., Wagner, J.
A series of (AlGaIn)N LEDs covering the 377 to 428 nm wavelength interval has been analyzed by pulsed electro- and temperature dependent photo-luminescence with respect to the carrier density...
Baeumler, M., Kunzer, M., Schmidt, R., Liu, S., Pletschen, W., Schlotter, P., ...
UV-to-violet emitting (AlGaln)N LEDs have been investigated with respect to the temperature-dependence of the output power characteristics and non-thermal rollover of the quantum efficiency at higher...
Meta-modelling for interoperability in product design (2007)
Interoperability of tools for product design relies on the utilization of common information models like ISO 10303 STEP. However STEP is based on the EXPRESS modelling language which is not supported...
Near-UV to violet LEDs - wavelength dependence of efficiency limiting processes (2007)
Kunzer, M., Kaufmann, U., Köhler, K., Liu, S., Wagner, J.
Two wavelength series (373-435 nm) of GaInN/GaN triple quantum well LED-structures, one on sapphire and one on GaN-templates, as well as a quantum well thickness series were grown by MOVPE. In order...
Layer manufacturing of micro components for 3D electrical interconnects. (2006)
Johander, P., Harrysson, U., Kaufmann, U., Ritzhaupt-Kleissl, H.J.
Micro Structure Workshop 2006, Västeras, S, May 9-10, 2006
Free form fabrication of 3D-ceramic parts with InkJet-printing. (2006)
Kaufmann, U., Harrysson, U., Johander, P., Bauer, W.
Vincenzini, P. [Hrsg.]
Design and manufacturing of micro heaters for gas sensors. (2006)
Johander, P., Goenaga, I., Gomez, D., Moldovan, C., Nedelcu, O., Petkov, P., ...
Dimov, S. [Hrsg.]
FASTFAB - a process for the free-form fabrication of 3D ceramic components. (2006)
Kaufmann, U., Ritzhaupt-Kleissl, H.J., Harrysson, U., Johander, P.
Ceramic Forum International: cfi/Berichte der Deutschen Keramischen Gesellschaft, 83(2006) Nr.13, S.13-17
In-vitro Untersuchung. Anwendung und Eigenschaften von biokompatiblem Zirkoniumdioxid. (2005)
Leutkirch : KaVo Everest`R Zirkonkeramik, 2005
Direct manufacture of ceramic micro components with layered manufacturing methods. (2005)
Johander, P., Harrysson, U., Kaufmann, U., Ritzhaupt-Kleissl, H.J.
Menz, W. [Hrsg.]
Mixed technologies for gas sensors microfabrication. (2005)
Moldovan, C., Sosin, S., Kaufmann, U., Ritzhaupt-Kleissl, H.J., Dimov, S., Petkov, P., ...
Menz, W. [Hrsg.]
Free Form Fabrication - Inkjet Printing Verfahren zur Herstellung von 3D-Keramikbauteilen. (2005)
Kaufmann, U., Harrysson, U., Johander, P.
Ceramic Forum International: cfi/Berichte der Deutschen Keramischen Gesellschaft, 82(2005) Nr.13, S.99-103
Free Form Fabrication: Ein Inkjet Printing-Verfahren zur Herstellung von 3D-Keramikbauteilen. (2005)
Kaufmann, U., Harrysson, U., Johander, P.
Symp.Hochleistungskeramik, Selb, 12.-13.Oktober 2005 (Poster)
Chemoresistive gas sensor manufacturing using mixed technologies. (2005)
Moldovan, C., Sosin, S., Nedelcu, O., Kaufmann, U., Ritzhaupt-Kleissl, H.J., Dimov, S., ...
2005 Internat.Semiconductor Conf., Sinaia, R, October 3-5, 2005
FASTFAB - ein Verfahren zur Herstellung frei geformter 3D-Keramikteile. (eingeladen) (2005)
Kaufmann, U., Ritzhaupt-Kleissl, H.J., Harrysson, U.
Greil, P. [Hrsg.]
Mikromechanische Keramikbearbeitung. (2005)
Gietzelt, T., Eichhorn, L., Kaufmann, U.
FIF-Newsletter, (2005) Dezember, S.4-6
III-N based short-wavelength LEDs, LUCO-LEDs and lasers (2004)
Sommer, F., Stephan, T., Vollrath, F., Köhler, K., Kunzer, M., Müller, S., ...
Results are presented on the effect of using GaN templates with homogeneously reduced defect density on the performance of violet- und UV-emitting (AlGaIn)N LEDs, as well as on the use of such LED...
Örlygsson, G., Finnah, G., Piotter, V., Kaufmann, U., Ruprecht, R., Hausselt, J.
James, W.B. [Hrsg.]
Kaufmann, U., Stolz, S., Ritzhaupt-Kleissl, H.J., Hausselt, J.
Werkstoffwoche 2004, München, 21.-23. September 2004 (Poster)
Jahrestagung der Deutschen Keramischen Gesellschaft, Karlsruhe, 11.-13.Oktober 2004
Verfahren zur Herstellung keramischer Mikrobauteile. (2004)
11.FIF-Workshop, Industrieforum Mikrofertigung, Karlsruhe, 28.-29.Oktober 2004
On the existence of positive solutions for periodic parabolic sublinear problems (2003)
We give necessary and sufficient conditions for the existence of positive solutions for sublinear Dirichlet periodic parabolic problems $Lu=g(x,t,u)$ in $\Omega\times\mathbb{R}$ (where...
On the existence of positive solutions for periodic parabolic sublinear problems (2003)
We give necessary and sufficient conditions for the existence of positive solutions for sublinear Dirichlet periodic parabolic problems Lu=g(x,t,u) in Ω×℠(where...
On the existence of positive solutions for periodic parabolic sublinear problems (2003)
We give necessary and sufficient conditions for the existence of positive solutions for sublinear Dirichlet periodic parabolic problems Lu=g(x,t,u) in Ω×ℝ (where Ω⊂ℝN is a smooth bounded...
Single chip white LEDs: Weiße Einzelchip-LEDs (2002)
Kaufmann, U., Kunzer, M., Köhler, K., Obloh, H., Pletschen, W., Schlotter, P., ...
The operation principles of the various single chip luminescence conversion (LUCO) white LEDs, that can be realized with blue or ultraviolet (UV) LED chips, are briefly reviewed. In order to...
Wagner, J., Kaufmann, U., Köhler, K., Kunzer, M., Pletschen, W., Obloh, H., ...
We report on the development of (AlGaIn)N quantum well LEDs covering the 380 to 430 nm wavelength range, which serve as the primary light source for tri-phosphor luminescence conversion white LEDs....
Multicomponent ceramic heaters. (2002)
Kaufmann, U., Ritzhaupt-Kleissl, H.
104th Annual Meeting and Exposition of the American Ceramic Society, St.Louis, Mo., April 28 - May 1, 2002
Ultraviolet pumped tricolor phosphor blend white emitting LEDs (2001)
Kaufmann, U., Kunzer, M., Köhler, K., Obloh, H., Pletschen, W., Schlotter, P., ...
Near-UV and violet emitting AlGaInN single quantum well LED structures were grown by MOCVD on sapphire substrates. On-wafer tests before processing gave an output power at 40 mA between 1.4 mW at 380...
Fast fabrication of ceramic microcomponents. (2001)
Kaufmann, U., Hausselt, J., Moritz, H.
mstnews, (2001) Nr.4, S.35-38
Hole conductivity and compensation in epitaxial GaN:Mg layers (2000)
Kaufmann, U., Schlotter, P., Obloh, H., Köhler, K., Maier, M.
The concentration p and the mobility mu of holes in metal-organic chemical vapor deposition (MOCVD) GaN:Mg layers were studied by room temperature Hall-effect measurements as a function of the Mg...
Group III-Nitride heterostructures: From materials research to devices (2000)
Wagner, J., Obloh, H., Kunzer, M., Schlotter, P., Pletschen, W., Kiefer, R., ...
Group III-nitride based heterostructures are of rapidly growing importance for the fabrication of short-wavelength light-emitting devices as well as for high-power high-frequency field effect...
Origin of defect-related photoluminescence bands in doped and nominally undoped GaN (1999)
Kaufmann, U., Kunzer, M., Obloh, H., Maier, M., Manz, C., Ramakrishnan, A., ...
The efficient room-temperature photoluminescence bands of wurtzite GaN, which are peaked in the red (1.8 eV), the yellow (2.2 eV), and the blue (2.8 eV) spectral range, have been studied as a...
Yoshikawa, M., Kunzer, M., Wagner, J., Obloh, H., Schlotter, P., Schmidt, R., ...
We have studied band-gap renormalization and band filling in Si-doped GaN films with free-electron concentrations up to 1.7 x 10(exp19) cm(-3) , using temperature-dependent photoluminescence (PL)...
Manz, C., Kunzer, M., Obloh, H., Ramakrishnan, A., Kaufmann, U.
The deep, yellow photoluminescence band well known in GaN has been studied in In(x)Ga(1-x)N (x
Group III-nitride based blue emitters (1999)
Obloh, H., Bachem, K.H., Behr, D., Kaufmann, U., Kunzer, M., Ramakrishnan, A., ...
(AlGaIn)N-based heterostructures are of considerable current interest for the realization of short-wave length light-emitting semiconductor devices, covering the UV- to-blue spectral region. Recent...
Urban, P., Stauffer, J-C., Bleed, D., Khatchatrian, N., Amann, W., Bertel, O., ...
Aim To test whether emergency revascularization improves survival in patients with acute myocardial infarction and shock. Methods and Results Patients with acute myocardial infarction and early shock...
Nature of the 2.8 eV photoluminescence band in Mg doped GaN (1998)
Kaufmann, U., Kunzer, M., Maier, M., Obloh, H., Ramakrishnan, A., Santic, B., ...
The blue Mg induced 2.8 eV photoluminescence (PL) band in metalorganic chemical vapor deposition grown GaN has been studied in a large number of samples with varying Mg content. It emerges near a Mg...
Modules and tools for virtual product realization (1998)
Jansen, H., Kaufmann, U., Neumann, J., Schumann, G., Ziebeil, P.
Kunzer, M., Kaufmann, U., Maier, M., Obloh, H.
Recombination paths in GaN/Al(x)Ga(1-x)N (x
Merz, C., Kunzer, M., Santic, B., Kaufmann, U., Akasaki, I., Amano, H.
The temperature dependence of free and bound exciton lines in high-purity, undoped wurtzite GaN layers has been studied by photoluminescence (PL) between 2 and 300 K. Below 30 K the neutral donor...
Niebuhr, R., Bachem, K.H., Behr, D., Hoffmann, C., Kaufmann, U., Lu, Y., ...
AlGaN/GaN single quantum wells (QW) have been grown on 2 sapphire substrates (c-plane) by metal-organic chemical vapor deposition (MOCVD). The well width was varied between 20 and 40 A.U. for...
Resonant Raman scattering in GaN/(AlGa)N single quantum wells (1997)
Behr, D., Niebuhr, R., Wagner, J., Bachem, K.H., Kaufmann, U.
Resonant Raman scattering has been used to study longitudinal optical (LO) phonon modes in 2-4-nm-wide GaN/Al(0.15)Ga(0.85)N single quantum wells (QW). Raman spectra recorded using subband gap...
Behr, D., Niebuhr, R., Obloh, H., Wagner, J., Bachem, K.H., Kaufmann, U.
We report on resonant Raman scattering in Al(0.15)Ga(0.85)N/GaN single quantum wells (QWs) and Al(x)Ga(1-x)N/GaN/In(y)Ga(1-y)N heterostructures. By choosing appropriate excitation conditions we could...
Kunzer, M., Baur, J., Kaufmann, U., Schneider, J., Amano, H., Akasaki, I.
We have studied the photoluminescence (PL) and optically detected magnetic resonance (ODMR) of undoped, n-doped and p-doped thin wurtzite GaN layers grown by metal-organic chemical vapor deposition...
Ionized donor bound excitons in GaN (1997)
Santic, B., Merz, C., Kaufmann, U., Niebuhr, R., Obloh, H., Bachem, K.
The temperature and excitation power dependence of a bound exciton photoluminescence line S with a localization energy Q=11.5 meV has been studied in undoped and moderately Mg-doped wurtzite GaN of...
Identification of multivalent molybdenum impurities in SiC crystals (1997)
Baur, J., Kunzer, M., Dombrowski, K.F., Kaufmann, U., Schneider, J., Baranov, P.G., ...
In this paper we summarize parts of our electron spin resonance (ESR) results on Mo(3+)and Mo(4+) centers in SiC polytypes. Further we present the identification of Mo(5+)in 6H-SiC via ESR. Thus Mo...
Electrical and optical properties of oxygen doped GaN grown by MOCVD using N2O (1997)
Niebuhr, R., Bachem, K.H., Kaufmann, U., Maier, M., Merz, C., Santic, B., ...
Oxygen doped GaN has been grown by metalorganic chemical vapor deposition using N2O as oxygen dopant source. The layers were deposited on 2" sapphire substrates from trimethylgallium and especially...
Light generating carrier recombination and impurities in wurtzite GaN/Al2O3 grown by MOCVD (1996)
Kaufmann, U., Kunzer, M., Merz, C., Akasaki, I., Amano, H.
We have studied by photoluminescence (PL) and optically detected magnetic resonance (ODMR) un- doped, n-doped and p-doped thin wurtzite GaN layers grown by metal-organic chemical vapor deposition on...
Kunzer, M., Dombrowski, K.F., Fuchs, F., Kaufmann, U., Schneider, J., Baranov, P.G., ...
In this work the identification of molybdenum trace impurities in commercial 6H-SiC substrates by conventional and optically detected electron spin resonance (ESR, ODESR), magnetic circular dichroism...
Identification of molybdenum in 6H-SiC by magnetic resonance techniques (1996)
Dombrowski, K.F., Kunzer, M., Kaufmann, U., Schneider, J.
We report on the identification of molybdenum trace impurities in commercial 6H-SiC substrates by conventional and optically detected electron spin resonance (ESR, ODESR) and magnetic circular...
Free and bound excitons in thin wurtzite GaN layers on sapphire (1996)
Merz, C., Kunzer, M., Kaufmann, U., Akasaki, I., Amano, H.
Free and bound excitons have been studied by photoluminescence in thin (1-10 microm) wurtzite-undoped GaN, n-type GaN:Si as well as p-type GaN:Mg and GaN:Zn layers grown by metal-organic chemical...
Photoluminescence of residual transition metal impurities in GaN (1995)
Baur, J., Kaufmann, U., Kunzer, M., Schneider, J.
A large number of epitaxial GaN samples as well as AlN ceramics have been studied by photoluminescence (PL) and PL excitation spectroscopy. In addition to the PL of residual iron, two new bands with...
Kunzer, M., Kaufmann, U., Maier, K., Schneider, J.
The magnetic circular dichroism (MCD) of the absorption has been studied in a 6H-SiC crystal highly contaminated with vanadium, V. In addition to previously reported MCD absorption lines of V...
Determination of the GaN/AlN band discontinuities via the '-/0' acceptor level of iron (1995)
Baur, J., Kunzer, M., Maier, K., Kaufmann, U., Schneider, J.
The 1.3 eV iron related emission bands in GaN and AlN were analysed by photoluminescence and photoluminescence excitation spectroscopy. The (-/0) acceptor levels of iron in GaN and AlN were...
Characterization of residual transition metal ions in GaN and AlN (1995)
Baur, J., Kaufmann, U., Kunzer, M., Schneider, J., Amano, H., Akasaki, I., ...
In this paper we present photoluminescence (PL), PL excitation and electron paramagnetic resonance (EPR) studies of residual transition metal impurities in a variety of doped and undoped wurtzite GaN...
Niebuhr, R., Bachem, K., Dombrowski, K., Maier, M., Pletschen, W., Kaufmann, U.
We have studied the growth of gallium nitride on c-plane sapphire substrates. The layers were grown in a horizontal metalorganic chemical vapor deposition reactor at atmospheric pressure using...
ODMR studies of MOVPE-grown GaN epitaxial layers. (1994)
Kunzer, M., Kaufmann, U., Maier, K., Schneider, J., Herres, N., Akasaki, I., ...
GaN epitaxial layers grown by MOVPE on Al2O3 substrates have been studied by optically detected magnetic resonance (ODMR) at 21 GHz. Undoped n-conducting, Mg doped high resistivity and Mg doped...
Iron acceptors in gallium nitride -GaN-. (1994)
Maier, K., Kunzer, M., Kaufmann, U., Schneider, J., Monemar, B., Akasaki, I., ...
We report on a combined study of the deep iron acceptor in vapour phase grown GaN epitaxial layers, on sapphire (alpha-Alsub2Osub3) substrate, by electron spin resonance (ESR) and optically detected...
Baur, J., Maier, K., Kunzer, M., Kaufmann, U., Schneider, J., Amano, H., ...
A characteristic infrared luminescence band, dominated by a zero-phonon line at 1.30 eV has been consistently detected in gallium nitride (GaN) epitaxial layers. It is assigned to the intra-3d-shell...
Dombrowski, K.F., Kaufmann, U., Kunzer, M., Maier, K., Schneider, J., Shields, V.B., ...
Nominally undoped zinc-blende polytype 3C-SiC single crystals have been studied by conventional electron-spin resonance (ESR), by the magnetic circular dichroism (MCD) absorption technique, and by...
Group-V antisite defects, VGa, in GaAs. (1994)
For more than a decade the interest ingroup-V antisite def ects in GaAs was focusing on the intrinsic AssubGa defect. More recently, when GaAs samples doped with isovalent group-V impurities became...
Determination of the GaN/AlN band offset via the -/0 acceptor level of iron (1994)
Baur, J., Maier, K., Kunzer, M., Kaufmann, U., Schneider, J.
A characteristic infrared luminescence spectrum, dominated by a zero-phonon line at 1.30 eV, has been observed on AlN polycrystalline material. It is assigned to the spin-forbidden internal 3d-3d...
Deep donor state of vanadium in cubic silicon carbide -3C-SiC- (1994)
Dombrowski, K.F., Kaufmann, U., Kunzer, M., Maier, K., Schneider, J., Shields, V.B., ...
Electron spin resonance (ESR) of silicon-substitutional vanadium in its neutral V (exp 4+)(ind Si) (3d (exp 1)) state has been observed in cubic bulk 3C-SiC single crystals. By photo-ESR the position...
Bistability of the Te donor in AlSb:Te bulk crystals (1994)
Jost, W., Kunzer, M., Kaufmann, U., Bender, H.
Photoenhanced electron-paramagnetic-resonance (EPR) and contactless photoconductivity measurements on Te-doped AlSb bulk crystals are reported. Low-temperature annealing studies of both photo-EPR and...
Semantisches Entwerfen in Verbindung mit AutoCAD (1993)
Es wird das System HyperDesign vorgestellt, das bei Entwurfstätigkeiten schon in frühen, konzeptuellen Stadien die geometrische Gestaltbeschreibung ermöglicht. Durch Kopplung dieses Systems mit...
Omling, P., Kveder, B.K., Meyer, B.K., Oettinger, K., Kaufmann, U., Kordina, O.
A strong, optically detected magnetic-resonance (ODMR) sign at g=1.99 is observed on the internal 3T2 to 3A2 emission of V3+. The ODMR excitation spectrum is identical with the emission spectrum....
Kunzer, M., Müller, H.D., Kaufmann, U.
Magnetic-circular-dichroism (MCD) absorption and optically detected electron-spin-resonance (ESR) data for the neutral vanadium impurity, Vhigh4plus(3dhigh1) on the alpha, beta and gamma sites in...
Identification of the BiGa heteroantisite defect in GaAs:Bi (1993)
Kunzer, M., Jost, W., Kaufmann, U., Hobgood, H.M., Thomas, R.N.
GaAS lightly doped with the heaviest group-V atom, bismuth (Bi), has been studied by conventional electron-spin resonance (ESR) and by ESR detected via the magnetic-circular-dichroism (MCD)...
Kunzer, M., Hendorfer, G., Köhler, K., Rühle, W.W., Kaufmann, U.
Optical pumping techniques and time-resolved photoluminescence have been used to study spin and exciton lifetimes in two pseudomorphic quantum well systems as a function of well width. From...
Kunzer, M., Hendorfer, G., Kaufmann, U., Köhler, K.
Circularly polarized excitation light from a tunable Ti-doped sapphire laser has been used to produce spin-polarized excitons in strained, pseudomorphic Insub0.16Gasub0.84As/Alsub0.29Gasub0.71As...
Magnetic resonance of x-point shallow donors in AlSb-Te bulk crystals and AlSb MBE layers. (1992)
Wilkening, W., Kaufmann, U., Schneider, J., Schönherr, E., Glaser, E.R., Shanabrook, B.V., ...
We report e lectron-paramagnetic-resonance (EPR) results for bulk AlSb:Te crystals as well as optically detected magnetic resonance (ODMR) data for molecular- beam-epitaxy (MBE) grown AlSb layers on...
Omling, P., Hofmann, D.M., Baeumler, M., Kaufmann, U., Kunzer, M.
In an investigation of GaAs doped with Sb to a concentration of approximately equal to 1 x 10high19 cmhighminus3, the electron-paramagnetic-resonance (EPR) signal of the SbsubGa heteroantisite defect...
Comparative study of the SbGa heteroantisite and off-center OAs in GaAs (1992)
Hendorfer, G., Bohl, B., Fuchs, F., Kaufmann, U., Kunzer, M.
The (O/plus) donor level of the SbsubGa heteroantisite and the off-center OsubAs-induced EL3 level in GaAs have very similar thermal emission rates for electrons and are therefore difficult to...
Jost, W., Kaufmann, U., Schneider, J., Köhler, K., Alt, H.C., Kunzer, M.
GaAs epitaxial layers grown by molecular beam epitaxy (MBE) at low temperature (LT) have been characterized by electron spin resonance (ESR) infrared absorption, magnetic circular dichroism (MCD) and...
Epitaxial growth of GdBa§2Cu§3O§7§-§x thin films on yttria-stabilized zirconia buffer layers. (1992)
Siegel, M., Wang, F., Smithey, R., Kaufmann, U., Linker, G., Meyer, O., ...
Correra, L. [Hrsg.]
Relative risk analysis of angiographic predictors of restenosis within the coronary Wallstent (1991)
Strauss, B.H., Scheerder, I.K. De, Tijssen, J.G.P., Bertrand, M.E., Puel, J., ...
BACKGROUND. Late angiographic narrowing has been observed following coronary implantation of the Wallstent. To identify the angiographic variables that predict restenosis within the stented segment,...
Kaufmann, U., Pfeifer, T., Schmidt, N.
Die Einführung Innovativer Technologien erfolgt grundsätzlich In mehreren Phasen. Sie stellt hohe Anforderungen an das begleitende Projektmanagement. Voraussetzung für die Einführung der...
Negative-U, off-center OAs in GaAs and its relation to the EL3 level (1991)
Klausmann, E., Schneider, J., Kaufmann, U., Alt, H.C.
Using comparative local-vibrational-mode and deep-level transient spectroscopy, we have studied the off-center O sub As defect in high-resistivity, undoped GaAs and neutron-transmutation-doped,...
Kinetics of holes optically excited from the AsGa EL2 midgap level in semi-insulating GaAs (1991)
Electron paramagnetic resonance (EPR) has been used to study the growth of the dominant acceptor EPR signals FR1 and GR2 in undoped semi-insulating GaAs under illumination as well as their...
Wilkening, W., Bauser, E., Kaufmann, U.
A new, light-induced electron paramagnetic resonance (EPR) signal with apparent tetragonal symmetry has been observed in n-type Alsub0.68Gasub0.32As:Sn layers grown on SI-GaAs. A comparison with...
Wilkening, W., Mooney, P.M., Kuech, T.F., Kaufmann, U.
We report electron-paramagnetic-resonance results for the shallow effective-mass 1s(T sub 2) state of the Si donor associated with the X valleys in indirect-band-gap (x equal or bigger than 0.4) Al...
The role of deep acceptors for the compensation of undoped SI GaAs: Chapter 1 (1990)
Baeumler, M., Mooney, P., Kaufmann, U., Wagner, J.
The equilibrium concentrations of singly ionized AsGa/EL2 have been found to exceed the shallow acceptor (C and Zn) concentrations in two series of LEC pBN-GaAs samples. This finding is attributed to...
We report electrom paramagnetic resonance (EPR) results for the shallow effective mass ground state 1s(T2) of the Si donor associated with the X valleys in indirect (x bigger than 0,4) AlxGa1-xAs:Si...
The spectroscopic evidence for the identity of EL2 and the AsGa antisite in As-grown GaAs. (1989)
EL2, the dominant deep defect in undoped as-grown GaAs has attracted tremendous interest because of its peculiar optical properties and because of its technological importance for the growth of...
Optical properties of the SbGa heteroantisite defect in GaAs:Sb (1989)
Baeumler, M., Fuchs, F., Kaufmann, U.
Photoelectron-paramagnetic-resonance and near-infrared-absorption measurements on antimony-doped GaAs:Sb are reported. The results provide convincing evidence that the E sub c - 0.48 eV level in this...
Baeumler, M., Schneider, J., Kaufmann, U., Meyer, B.
Both neutral (A0) and ionized (A minus) manganese acceptor states in p-GaAs:Mn were analysed by optically detected magnetic resonance (ODMR) via ESR-induced changes in the magnetic circular dichroism...
Electron parametric-resonance measurements of Si-donor-related levels in Al(x)Ga(1-x)As (1989)
Mooney, P.M., Wilkening, W., Kuech, T.F., Kaufmann, U.
We report measurements of an EPR signal in indirect-gap Si-doped Alx Ga1-xAs whose intensity increases after illumination at low temperature. The data indicate that this signal comes from a...
Electron parametric resonance identification of the SbGa heteroantisite defect in GaAs:Sb (1989)
Baeumler, M., Schneider, J., Mitchel, W.C., Yu, P.W., Kaufmann, U.
GaAs doped with antimony (Sb) to a level of 10 high 19 cm high minus 3 has been studied by electron paramagnetic resoncance (EPR). A new EPR spectrum has been discovered which is identified as the Sb...
Baeumler, M., Mooney, P.M., Kaufmann, U.
A new photoexcitation band of the FR3 EPR signal in undoped semiinsulating GaAs has been discovered. It results from the excitation of an electron from the FR3 acceptor level to the conduction band....
Brunthaler, G., Jantsch, W., Schneider, J., Kaufmann, U.
Application of electron paramagnetic resonance to neutron-irradiated CdTe shows the presence of a new centre, labelled XA, having mirror symmetry Cs. In terms of a spin Hamiltonian for an effective...
Photo response of the EL2 absorption band and of the As+Ga ESR signal in GaAs (1988)
The photo response of the EL2 absorption band and of the As+ Ga ESR signal in GaAs is described and compared with the basic optical properties of the EL2 mid-gap level, as inferred from...
A simple theoretical model for the magnetic circular dichroism absorption (MCDA) of as-grown semiinsulating GaAs is proposed. It is shown that the MCDA spectrum can be explained in terms of the...
Origin of the magnetic-circular-dichroism absorption of undoped as-grown GaAs (1988)
It is shown that the below-band-gap magnetic-circular-dichroism absorption of as-grown semi-insulating GaAs can be explained in terms of the photoneutralization transition, As+ sub Ga + h ny....As(o)...
Photo response of the EL2 absorption band and of the As+Ga ESR signal in GaAs (1988)
The photo response of the EL2 absorption band and of the As+ Ga ESR signal in GaAs is described and compared with the basic optical properties of the EL2 mid-gap level, as inferred from...
Photo response of the EL2 absorption band and of the As+Ga ESR signal in GaAs (1988)
The photo response of the EL2 absorption band and of the As+ Ga ESR signal in GaAs is described and compared with the basic optical properties of the EL2 mid-gap level, as inferred from...
Prevention of coronary restenosis by stenting (1988)
Sigwart, U., Kaufmann, U., Grbic, M., Golf, S., Essinger, A., ...
Balloon angioplasty fails to provide acceptable long-term results for a significant proportion of patients. An intravascular mechanical support, developed with the aim of preventing restenosis and...
Photoresponse of the FR3 electron-spin-resonance signal in GaAs (1987)
Wilkening, W., Baeumler, M., Kaufmann, U.
The photoresponse of the FR3 electron-spin-resonance (ESR) signal in GaAs has been studied. Excitation and quenching of the FR3 ESR is shown to result from the optically induced charge exchange...
Electronic structure of the neutral manganese acceptor in gallium arsenide (1987)
Schneider, J., Wilkening, W., Baeumler, M., Köhl, F., Kaufmann, U.
A new manganese-related isotropic electron-spin-resonance signal at g=2.77 has been observed in GaAs. It is shown to arise from the neutral Mn acceptor, MnE0. The analysis gives an answer to the...
Identifizierung und Charakterisierung von Punktdefekten in GaAs und InP (1986)
Baeumler, M., Pomrenke, G., Schneider, J., Kaufmann, U., Müller, H., Ennen, H., ...
Photo-EPR of defects in undoped semiinsulating GaAs (1986)
Baeumler, M., Wilkening, W., Kaufmann, U., Windscheif, J.
Electron paramagnetic resonance spectra of as-grown, semi-insulating LEC GaAs at 9 GHz and 35 GHz have revealed three high intensity signals presumably associated with acceptor type defects. The...
New photosensitive EPR signals in undoped semi-insulating GaAs (1986)
Baeumler, M., Kaufmann, U., Windscheif, J.
Three new EPR signals labelled FR1, FR2 and FR3 have been observed in undoped as grown LEC GaAs. They are well observable only below 10K, their intensities are high and they appear only after optical...
Baeumler, M., Wilkening, W., Kaufmann, U., Windscheif, J.
Electron paramagnetic resonance studies on as-grown semi-insulating liquid encapsulation Czochralski (LEC) GaAs at 35 GHz have revealed a new resonance labeled FR3. It is consistently present in LEC...
Electron tunneling into Nb§3Sn, Nb§3Ge, and Nb§3Al. (1986)
Geerk, J., Kaufmann, U., Bangert, W., Rietschel, H.
Physical Review B, 33(1986) S.1621-26
Zeeman analysis of the ytterbium luminescence in indium phosphide (1985)
Schneider, J., Aszodi, G., Weber, J., Pu-lin, L., Kaufmann, U., Uihlein, C., ...
Touristische Transportanlagen der Schweiz = Installations de transport touristiques en Suisse (1985)
Electrical and optical properties of the neutral nickel acceptor in gallium phosphide. (1984)
Peaker, A.R., Woerner, R., Hamilton, B., Grimmeiss, H.G., Kaufmann, U.
Concentration and thermal stability of As tief Ga in GaAs - Correlation with EL2 (1984)
Baeumler, M., Schneider, J., Koehl, F., Kaufmann, U., Windscheif, J.
Rare earth activated luminescence in InP, GaP and GaAs. (1983)
Pomrenke, G., Schneider, J., Axmann, A., Kaufmann, U., Ennen, H., Windscheif, J.
Endor investigation of Ni 3+ in GaP (1983)
Schneider, J., Ueda, Y., Niklas, J.R., Spaeth, J.M., Kaufmann, U.
Annealing behavior of the 0.8 eV luminescence in undoped semiinsulating GaAs (1983)
Schneider, J., Kimura, T., Kaufmann, U., Ennen, H., Windscheif, J.
Spectroscopic study of vanadium in GaP and GaAs (1982)
Schneider, J., Wörner, R., Weber, J., Köhl, F., Kaufmann, U., Ennen, H.
ELECTRON-SPIN-RESONANCE AND OPTICAL ABSORPTION OF Ni+ AND Ti3+ IN IB-III-S2 COMPOUNDS (1975)
Kaufmann, U., RÄuber, A., Schneider, J.
Electron-Spin-Resonance (ESR) and optical absorption of Ni+(3d9) has been observed in CuAlS2, CuGaS2 and AgGaS2. Identification of the axial ESR centers as being due to Ni has been confirmed by the...
ELECTRON-SPIN-RESONANCE AND OPTICAL ABSORPTION OF Ni+ AND Ti3+ IN IB-III-S2 COMPOUNDS (1975)
Kaufmann, U., RÄuber, A., Schneider, J.
Electron-Spin-Resonance (ESR) and optical absorption of Ni+(3d9) has been observed in CuAlS2, CuGaS2 and AgGaS2. Identification of the axial ESR centers as being due to Ni has been confirmed by the...
ELECTRON-SPIN-RESONANCE AND OPTICAL ABSORPTION OF Ni+ AND Ti3+ IN IB-III-S2 COMPOUNDS (1975)
Kaufmann, U., RÄuber, A., Schneider, J.
Electron-Spin-Resonance (ESR) and optical absorption of Ni+(3d9) has been observed in CuAlS2, CuGaS2 and AgGaS2. Identification of the axial ESR centers as being due to Ni has been confirmed by the...
Wagdi, P., Kaufmann, U., Fluri, M., Meier, B.
AIM: To validate dipyridamole as a pharmacological stress test during cardiac catheterisation, allowing both functional and morphological estimation of stenosis severity. METHODS: The study...
Ramamurthy, S., Mehan, V., Kaufmann, U., Verin, V., Lüscher, T. F., Meier, B.
OBJECTIVE: In the light of the reported inconsistent anti-ischaemic and antianginal effects of transdermal glyceryl trinitrate, its efficacy and influence on the effects of intracoronary glyceryl...