TY - JOUR A1 - Stahn, Jochen A1 - Pucher, Andreas A1 - Pietsch, Ullrich A1 - Zellner, J. A1 - Weckert, E. T1 - Experimental determination of electric field induced differences in structure factor phases in the order of 2% Y1 - 1999 ER - TY - JOUR A1 - Struth, Bernd A1 - Decher, Gero A1 - Schmitt, J. A1 - Hofmeister, Wolfgang A1 - Neißendorfer, Frank A1 - Pietsch, Ullrich A1 - Brezesinski, Gerald A1 - Möhwald, Helmuth T1 - Chemical modification of Topaz surfaces Y1 - 1999 SN - 0928-4931 ER - TY - JOUR A1 - Stömmer, Ralph A1 - Göbel, H. A1 - Hub, W. A1 - Pietsch, Ullrich T1 - X-ray scattering from silicon surfaces Y1 - 1998 ER - TY - JOUR A1 - Stömmer, Ralph A1 - Martin, C. R. A1 - Geue, Thomas A1 - Göbel, H. A1 - Hub, W. A1 - Pietsch, Ullrich T1 - Comparative studies of fractal parameters of Si(100) surfaces measured by X-ray scattering and atomic force microscopy Y1 - 1998 ER - TY - JOUR A1 - Stömmer, Ralph A1 - Zeimer, Ute A1 - Pietsch, Ullrich T1 - Diffuse Röntgenstreuung an LB-Filmen Y1 - 1995 ER - TY - JOUR A1 - Talalaev, V A1 - Tomm, JW A1 - Elsaesser, T A1 - Zeimer, Ute A1 - Fricke, J A1 - Knauer, A A1 - Kissel, H A1 - Weyers, Markus A1 - Tarasov, GG A1 - Grenzer, Jörg A1 - Pietsch, Ullrich T1 - Carrier dynamics in laterally strain-modulated InGaAs quantum wells N2 - We investigate the transient recombination and transfer properties of nonequilibrium carriers in an In0.16Ga0.84As/GaAs quantum well (QW) with an additional lateral confinement implemented by a patterned stressor layer. The structure thus contains QW- and quantum-wire-like areas. At low excitation densities, photoluminescence (PL) transients from both areas are well described by a rate equation model for a three-level system with a saturable interlevel carrier transfer representing the lateral drift of carriers from the QW regions into the wires. Small-signal carrier lifetimes for QW, wires, and transfer time from QW to wire are 180, 190, and 28 ps, respectively. For high excitation densities the time constants of the observed transients increase, in agreement with the model. In addition, QW and wire PL lines merge indicating a smoothening of the potential difference, i.e., the effective carrier confinement caused by the stressor structure becomes weaker with increasing excitation. (c) 2005 American Institute of Physics Y1 - 2005 ER - TY - JOUR A1 - Thünemann, Andreas F. A1 - Kubowicz, Stephan A1 - Pietsch, Ullrich T1 - Ultra-thin solid polyelectrolyte-surfactant complex films : structure and wetting Y1 - 2000 ER - TY - JOUR A1 - Tsirelson, Vladimir G. A1 - Abramov, Yury Fedorovich A1 - Zavodnik, Valerie E. A1 - Stash, Adam I. A1 - Belokoneva, Elena L. A1 - Stahn, Jochen A1 - Pietsch, Ullrich A1 - Feil, Dirk T1 - Critical pionts in a crystal an procrystal Y1 - 1998 ER - TY - JOUR A1 - Tsirelson, Vladimir G. A1 - Avilov, Anatoly S. A1 - Lepeshov, G. G. A1 - Kuligin, A. K. A1 - Stahn, Jochen A1 - Pietsch, Ullrich A1 - Spence, J. C. H. T1 - Quantitative Analysis of the Inner-Crystal Electrostatic Potential of several Rock-Salt-Structure Crystals Using Accurate Electron-Diffraction Data Y1 - 2001 SN - 1089-5647 ER - TY - JOUR A1 - Ulyanenkov, A. A1 - Baumbach, Tilo A1 - Darowski, Nora A1 - Pietsch, Ullrich A1 - Wang, K. H. A1 - Forchel, Alfred A1 - Wiebach, T. T1 - Investigation of the in-plane strain distribution in free-standing GaAs/InGaAs/GaAs single quantum well surface nanostructures on GaAs[001] Y1 - 1999 ER - TY - JOUR A1 - Ulyanenkov, A. A1 - Darowski, Nora A1 - Grenzer, Jörg A1 - Pietsch, Ullrich A1 - Wang, K. H. A1 - Forchel, Alfred T1 - Evaluation of strain distribution in freestanding and bruied lateral nanostructures Y1 - 1999 ER - TY - JOUR A1 - Ulyanenkov, A. A1 - Klemradt, U. A1 - Pietsch, Ullrich T1 - Investigation of strain relaxation in GaInAs/GaAs superlattices by x-ray diffuse scattering Y1 - 1998 ER - TY - JOUR A1 - Veldkamp, Markus A1 - Erko, Alexei A1 - Gudat, Wolfgang A1 - Abrosimov, Nikolai V. A1 - Alex, Volker A1 - Khasanov, Salavat A1 - Neissendorfer, Frank A1 - Pietsch, Ullrich A1 - Shekhtman, Veniamin T1 - Si(1-x)Ge(x) laterally graded crystals as monochromators for X-Ray absorption spectroscopy studies Y1 - 1999 ER - TY - JOUR A1 - Zeimer, Ute A1 - Baumbach, Tilo A1 - Grenzer, Jörg A1 - Lübbert, Daniel A1 - Mazuelas, A. A1 - Pietsch, Ullrich A1 - Erbert, G. T1 - In-situ characterization of strain distribution in broad-area high-power lasers under operation by high- resolution x-ray diffrcation and topography using synchrotron radiation Y1 - 1999 ER - TY - JOUR A1 - Zeimer, Ute A1 - Bugge, F. A1 - Gramlich, S. A1 - Smirnitzki, V. A1 - Weyers, Markus A1 - Tränkle, G. A1 - Grenzer, Jörg A1 - Pietsch, Ullrich A1 - Cassabois, G. A1 - Emiliani, V. A1 - Lienau, C. T1 - Evidence for strain-induced lateral carrier confinement in InGaAs quantum wells by low-temperature near-field spectroscopy Y1 - 2000 ER - TY - JOUR A1 - Zeimer, Ute A1 - Bugge, F. A1 - Gramlich, S. A1 - Smirnitzki, V. A1 - Weyers, Markus A1 - Tränkle, G. A1 - Grenzer, Jörg A1 - Pietsch, Ullrich A1 - Cassabois, G. A1 - Emiliani, V. A1 - Linau, Christoph T1 - Evidence of strain-induced lateral carrier confinement in InGaAs-quantum wells by low-temperature near-field spectroscopy Y1 - 2001 ER - TY - JOUR A1 - Zeimer, Ute A1 - Grenzer, Jörg A1 - Pietsch, Ullrich A1 - Bugge, F. A1 - Smirnitzki, V. A1 - Weyers, Markus T1 - Investigation of strain-modulated InGaAs-nanostructures by grazing-incidence x-ray diffraction and photoluminescence Y1 - 2001 ER - TY - JOUR A1 - Zeimer, Ute A1 - Pietsch, Ullrich A1 - Grenzer, Joerg A1 - Fricke, J. A1 - Knauer, A. A1 - Weyers, Markus T1 - Optimised two layer overgrowth of a lateral strain-modulated nanostructure N2 - Recently it has been shown that lateral carrier confinement in an InGaAs quantum well (QW) embedded in GaAs can be achieved by using a laterally patterned InGaP stressor layer on top of the heterostructure. To exploit this effect in a device the structure has to be planarized by a second epitaxial step. It has been shown that the lateral strain modulation almost vanishes after overgrowth with GaAs, whereas overgrowth with a single ternary layer of opposite strain compared to the stressor layer suffers from strain induced decomposition. Here we show that the lateral carrier confinement of the initially free standing nanostructure can almost be maintained using a two step process for overgrowth, where a strained thin ternary layer is grown first followed by GaAs up to complete planarization of the patterned structure. Thickness and composition of the ternary layer are adjusted on the basis of finite element calculations of the strain distribution (FEM). The strain field achieved after overgrowth is probed by X-ray grazing- incidence diffraction (GID). (c) 2005 Elsevier B.V. All rights reserved Y1 - 2005 SN - 0925-8388 ER - TY - JOUR A1 - Zhuang, Y. A1 - Holý, Václav A1 - Stangl, Jochen A1 - Darhuber, A. A1 - Mikulik, P. A1 - Zerlauth, S. A1 - Schäffler, F. A1 - Bauer, Günther A1 - Darowski, Nora A1 - Lübbert, Daniel A1 - Pietsch, Ullrich T1 - Strain relaxation in periodic arrays of Si/SiGe quantum wires determined by coplanar high-resolution x-ray diffrcation and grazing-incidence diffraction Y1 - 1999 ER - TY - JOUR A1 - Zhuang, Y. A1 - Pietsch, Ullrich A1 - Stangl, Jochen A1 - Holý, Vaclav A1 - Darowski, Nora A1 - Grenzer, Jörg A1 - Zerlauth, S. A1 - Schäffler, F. A1 - Bauer, Günther T1 - In-plane strain and shape analysis of Si/SiGe nanostructures by grazing incidence diffraction Y1 - 2000 ER - TY - JOUR A1 - Zhuang, Y. A1 - Schelling, Christoph A1 - Stangl, Jochen A1 - Penn, C. A1 - Senz, S. A1 - Schäffler, Friedrich A1 - Roche, T. A1 - Daniel, A. A1 - Grenzer, Jörg A1 - Pietsch, Ullrich A1 - Bauer, Günther T1 - Structural and optical properties of Si/Si{1-x}Ge{x} wires Y1 - 2000 ER -