@article{GrenzerDarowskiGeueetal.2001, author = {Grenzer, J{\"o}rg and Darowski, Nora and Geue, Thomas and Pietsch, Ullrich and Daniel, A. and Rennon, Siegfried and Reithmaier, Johann-Peter and Forchel, Alfred}, title = {Strain analysis and quantum well intermixing of a laterally modulated multiquantum well system produced by focused ion beam implantation}, year = {2001}, language = {en} } @article{ZenBilgeGalbrechtetal.2006, author = {Zen, Achmad and Bilge, Askin and Galbrecht, Frank and Alle, Ronald and Meerholz, Klaus and Grenzer, J{\"o}rg and Neher, Dieter and Scherf, Ullrich and Farrell, Tony}, title = {Solution processable organic field-effect transistors utilizing an alpha,alpha '-dihexylpentathiophene- based swivel cruciform}, doi = {10.1021/Ja0573357}, year = {2006}, language = {en} } @article{PietschHazraChinietal.2004, author = {Pietsch, Ullrich and Hazra, S. and Chini, T. K. and Sanyal, M. K. and Grenzer, J{\"o}rg}, title = {Ripple structure of crystalline layers in ion beam induced Si wafers}, year = {2004}, abstract = {Ion-beam-induced ripple formation in Si wafers was studied by two complementary surface sensitive techniques, namely atomic force microscopy (AFM) and depth-resolved x-ray grazing incidence diffraction (GID). The formation of ripple structure at high doses (similar to7x10(17) ions/cm(2)), starting from initiation at low doses (similar to1x10(17) ions/cm(2)) of ion beam, is evident from AFM, while that in the buried crystalline region below a partially crystalline top layer is evident from GID study. Such ripple structure of crystalline layers in a large area formed in the subsurface region of Si wafers is probed through a nondestructive technique. The GID technique reveals that these periodically modulated wavelike buried crystalline features become highly regular and strongly correlated as one increases the Ar ion-beam energy from 60 to 100 keV. The vertical density profile obtained from the analysis of a Vineyard profile shows that the density in the upper top part of ripples is decreased to about 15\% of the crystalline density. The partially crystalline top layer at low dose transforms to a completely amorphous layer for high doses, and the top morphology was found to be conformal with the underlying crystalline ripple}, language = {en} } @article{PietschGrenzerGrigorianetal.2004, author = {Pietsch, Ullrich and Grenzer, J{\"o}rg and Grigorian, Souren A. and Weyers, Markus and Zeimer, Ute and Feranchuk, S. and Fricke, J. and Kissel, H. and Knauer, A. and Tr{\"a}nkle, G.}, title = {Nanoengineering of lateral strain-modulation in quantum well heterostructures}, year = {2004}, abstract = {We have developed a method to design a lateral band-gap modulation in a quantum well heterostructure. The lateral strain variation is induced by patterning of a stressor layer grown on top of a single quantum well which itself is not patterned. The three-dimensional (3D) strain distribution within the lateral nanostructure is calculated using linear elasticity theory applying a finite element technique. Based on the deformation potential approach the calculated strain distribution is translated into a local variation of the band-gap energy. Using a given vertical layer structure we are able to optimize the geometrical parameters to provide a nanostructure with maximum lateral band-gap variation. Experimentally such a structure was realized by etching a surface grating into a tensile-strained InGaP stressor layer grown on top of a compressively strained InGaAs-single quantum well. The achieved 3D strain distribution and the induced band-gap variation are successfully probed by x-ray grazing incidence diffraction and low-temperature photoluminescence measurements, respectively}, language = {en} } @article{ZeimerGrenzerPietschetal.2001, author = {Zeimer, Ute and Grenzer, J{\"o}rg and Pietsch, Ullrich and Bugge, F. and Smirnitzki, V. and Weyers, Markus}, title = {Investigation of strain-modulated InGaAs-nanostructures by grazing-incidence x-ray diffraction and photoluminescence}, year = {2001}, language = {en} } @article{KarcenkoEnglischGrenzeretal.2000, author = {Karcenko, Anatolij V. and Englisch, Uwe and Grenzer, J{\"o}rg and Geue, Thomas and Pietsch, Ullrich and Siebrecht, R.}, title = {Investigation of partially deuterated multilayers by means of X-ray and polarized neutron reflectometry}, issn = {1044-8632}, year = {2000}, language = {en} } @article{StahnGeueGrenzeretal.2000, author = {Stahn, Jochen and Geue, Thomas and Grenzer, J{\"o}rg and Pietsch, Ullrich}, title = {Interaction of short-chain alkanes with surface and interfaces of multilayer films built from amphiphilic molecules: an in-situ X-ray and neutron scattering probe}, year = {2000}, language = {en} } @article{PietschZeimerGrenzeretal.2003, author = {Pietsch, Ullrich and Zeimer, Ute and Grenzer, J{\"o}rg and Grigorian, Souren A. and Fricke, J. and Gramlich, S. and Bugge, F. and Weyers, Markus and Trankle, G.}, title = {Influence of lateral patterning geometry on lateral carrier confinement in strain-modulated InGaAs- nanostructures}, year = {2003}, language = {en} } @article{ZeimerBaumbachGrenzeretal.1999, author = {Zeimer, Ute and Baumbach, Tilo and Grenzer, J{\"o}rg and L{\"u}bbert, Daniel and Mazuelas, A. and Pietsch, Ullrich and Erbert, G.}, title = {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}, year = {1999}, language = {en} } @article{ZhuangPietschStangletal.2000, author = {Zhuang, Y. and Pietsch, Ullrich and Stangl, Jochen and Hol{\´y}, Vaclav and Darowski, Nora and Grenzer, J{\"o}rg and Zerlauth, S. and Sch{\"a}ffler, F. and Bauer, G{\"u}nther}, title = {In-plane strain and shape analysis of Si/SiGe nanostructures by grazing incidence diffraction}, year = {2000}, language = {en} }