@inproceedings{4109, author = {{Pauly, Johannes and Lindner, Jörg}}, location = {{Regensburg (Germany)}}, title = {{{Nickel Nanodot Arrays on Silicon formed by Nanosphere Lithography: A TEM Study}}}, year = {{2013}}, } @inproceedings{4110, author = {{Riedl, Thomas and Lindner, Jörg}}, location = {{Boston (USA)}}, title = {{{Self-organized Fabrication of Periodic Nanocolumn Arrays on GaAs Surfaces}}}, year = {{2013}}, } @article{4111, abstract = {{In this article we study the elemental distribution and solute solubility in nanocrystalline alloys of immiscible components near restricted equilibrium for the case of the binary Cu–Ag system. As predicted from thermodynamic considerations, a grain boundary segregated monophase alloy is observed in the annealed mechanically alloyed state for low Ag content by using atom probe tomography. From the detected Ag solute grain boundary enrichment the segregation free enthalpy is estimated to range between -25 and -49 kJ mol^-1 following the McLean equation, in agreement with values reported for coarse-grained Cu–Ag. The extension of the alloying range is described by a two-domain thermodynamic model that considers the excess free volume in the grain boundaries and the strain in the strain interior on the basis of the universal equation of state at negative pressure. To access the grain boundary volumetric strain experimentally, a method based on a combination of density measurements and microscopical quantification of closed pore areas is presented. Moreover, we apply x-ray diffraction line broadening analysis to determine the local strain amplitude, which yields a root-mean-square microstrain of 0.3% for a grain size of 30 nm. It is shown that the grain boundary free volume represents the major origin for the global solubility enhancement in nanocrystalline Cu–Ag at 503 K.}}, author = {{Riedl, Thomas and Kirchner, A and Eymann, K and Shariq, A and Schlesiger, R and Schmitz, G and Ruhnow, M and Kieback, B}}, issn = {{0953-8984}}, journal = {{Journal of Physics: Condensed Matter}}, number = {{11}}, publisher = {{IOP Publishing}}, title = {{{Elemental distribution, solute solubility and defect free volume in nanocrystalline restricted-equilibrium Cu–Ag alloys}}}, doi = {{10.1088/0953-8984/25/11/115401}}, volume = {{25}}, year = {{2013}}, } @inproceedings{4113, author = {{Lindner, Jörg}}, location = {{Kusadasi (Turkey)}}, title = {{{Ion Interactions with Nanopatterned Surfaces}}}, year = {{2013}}, } @article{4095, abstract = {{Aiming to diminish the reflection losses of glass covered light harvesting devices, the optical reflectivity of nanostructured glass surfaces is studied theoretically and experimentally. The work is inspired by the nanoscale roughness of insect eyes, which is tried to be replicated on a technical glass surface. To this end, the reflectivity of glass surfaces with topographies represented by linear, parabolic and Fermishaped glass/air fill factor profiles is calculated for normal incidence. It is shown that using the latter ones, an almost complete suppression of reflections can be achieved. A simple, self-organization technique to create such Fermi-shaped filling factor profiles in glass experimentally is also presented.}}, author = {{Achtelik, J. and Sievers, W. and Lindner, Jörg}}, issn = {{0921-5107}}, journal = {{Materials Science and Engineering: B}}, location = {{Straßburg (France)}}, number = {{9}}, pages = {{635--638}}, publisher = {{Elsevier BV}}, title = {{{Biomimetic approaches to create anti-reflection glass surfaces for solar cells using self-organizing techniques}}}, doi = {{10.1016/j.mseb.2012.10.014}}, volume = {{178}}, year = {{2012}}, } @article{4114, abstract = {{Two methods to create biomimetic anti-reflection nanostructures in ordinary glass microscope object slides are presented. One technique is based on a nanosphere lithography process combined with physical vapour deposition of nickel and reactive ion etching (RIE). The other uses plasma induced dewetting of a smooth nickel surface. The amount of reflected light was measured and a method to simulate the reflectivity from an atomic force microscopy (AFM) topography scan of the glass surface is presented. The reflectivity for visible light at normal incidence was reduced to 20-50 % of the original value with both methods and the simulation gives results in good agreement to the measurement.}}, author = {{Achtelik, Jörn and Kemper, Ricarda M. and Sievers, Werner and Lindner, Jörg}}, issn = {{1946-4274}}, journal = {{MRS Proceedings}}, location = {{Boston (USA)}}, publisher = {{Cambridge University Press (CUP)}}, title = {{{Self-Organized Nanostructure Formation for Anti-Reflection Glass Surfaces}}}, doi = {{10.1557/opl.2012.491}}, volume = {{1389}}, year = {{2012}}, } @inproceedings{4115, author = {{Brodehl, Christoph and Greulich-Weber, Siegmund and Lindner, Jörg}}, location = {{Paderborn}}, title = {{{Gyrotropic Metamaterials}}}, year = {{2012}}, } @article{4131, abstract = {{We report an anisotropic formation of defects in cubic GaN grown on nano-patterned 3C-SiC/Si (001) by molecular beam epitaxy. Nano-patterning of 3C-SiC/Si (001) is achieved by nanosphere lithography and a reactive ion etching process. Atomic force microscopy and scanning electron microscopy show that the selectivearea- grown cubic GaN nucleates in two structurally different domains, which most probably originate from the substrate. In adjacent domains the formation of defects, especially hexagonal inclusions, is different and leads to two different surface morphologies. The dominant phase within these domains was measured by electron backscatter diffraction. Optical properties were investigated by micro-photoluminescence and cathodoluminescence spectroscopy.}}, author = {{Kemper, R. M. and Häberlen, M. and Schupp, T. and Weinl, M. and Bürger, M. and Ruth, M. and Meier, Cedrik and Niendorf, T. and Maier, H. J. and Lischka, K. and As, D. J. and Lindner, Jörg}}, issn = {{1862-6351}}, journal = {{physica status solidi (c)}}, number = {{3-4}}, pages = {{1028--1031}}, publisher = {{Wiley}}, title = {{{Formation of defects in cubic GaN grown on nano-patterned 3C-SiC (001)}}}, doi = {{10.1002/pssc.201100174}}, volume = {{9}}, year = {{2012}}, } @inproceedings{4133, author = {{Kemper, R.M. and Hiller, L. and Stauden, T. and Pezoldt, J. and Meertens, D. and Luysberg, M. and Tillmann, K. and Riedl, Thomas and As, Donald and Lindner, Jörg}}, location = {{Manchester (UK)}}, title = {{{TEM investigation of GaN thin films grown on nanostructured 3C-SiC/Si(001) substrates}}}, year = {{2012}}, } @inproceedings{4134, author = {{Lindner, Jörg}}, location = {{Warsaw (Poland)}}, title = {{{Nanosphere Lithography: State-of-the-art and Future Directions}}}, year = {{2012}}, } @inproceedings{4135, author = {{Pauly, Johannes and Lindner, Jörg}}, location = {{Warsaw (Poland)}}, title = {{{TEM Characterization of Nickel Nanodot Arrays on Silicon formed by Nanosphere Lithography}}}, year = {{2012}}, } @inproceedings{4138, author = {{Lindner, Jörg}}, location = {{Oberkochen und Jena (online)}}, title = {{{Nanokugellithographie: Grundlagen und Anwendungen}}}, year = {{2012}}, } @inproceedings{4139, author = {{Lindner, Jörg}}, location = {{Leipzig (Germany)}}, title = {{{Nanolithographie von Oberflächen für das Wachstum optoelektronischer Strukturen}}}, year = {{2012}}, } @article{4116, abstract = {{Anisotropic etching processes for mesa structure formation using fluorinated plasma atmospheres in an electron cyclotron resonance (ECR) plasma etcher were studied on Novasic substrates with 10 μm thick 3C-SiC(100) grown on Si(100). To achieve reasonable etching rates, a special gas inlet system suitable for injecting SF6 into the high density downstream Ar ECR plasma was designed. The influence of the etching mask material on the sidewall morphology was investigated. Masking materials with small grain sizes are preferable to achieve a desired shape. The evolution of the mesa form was investigated in dependence on the gas composition, the applied bias, the pressure and the composition of the gas atmosphere. The achieved sidewall slope was 84.5 deg. The aspect ratios of the fabricated structures in the developed residue free ECR plasma etching process were between 5 and 10. Mesa structures aligned to [100] and [110] directions were fabricated.}}, author = {{Hiller, Lars and Stauden, Thomas and Kemper, Ricarda M. and Lindner, Jörg and As, Donat J. and Pezoldt, Jörg}}, issn = {{1662-9752}}, journal = {{Materials Science Forum}}, location = {{Cleveland (USA)}}, pages = {{901--904}}, publisher = {{Trans Tech Publications}}, title = {{{ECR-Ectching of Submicron and Nanometer Sized 3C-SiC(100) Mesa Structures}}}, doi = {{10.4028/www.scientific.net/msf.717-720.901}}, volume = {{717-720}}, year = {{2012}}, } @article{4104, abstract = {{We report on the molecular beam epitaxy growth of cubic GaN on 3C–SiC (001) nanostructures. Transmission electron microscopy (TEM) studies show phase-pure cubic GaN crystals with a low defect density on top of the post shaped 3C–SiC nanostructures and GaN grown on their sidewalls, which is dominated by {111} planar defects. The nanostructures, aligned parallel and perpendicular to the [110] directions of the substrate, are located in anti-phase domains of the 3C–SiC/Si (001) substrate. These anti-phase domains strongly influence the optimum growth of GaN layers in these regions. TEM measurements demonstrate a different stacking fault density in the cubic GaN epilayer in these areas.}}, author = {{Kemper, R.M. and Hiller, L. and Stauden, T. and Pezoldt, J. and Duschik, K. and Niendorf, T. and Maier, H.J. and Meertens, D. and Tillmann, K. and As, D.J. and Lindner, Jörg}}, issn = {{0022-0248}}, journal = {{Journal of Crystal Growth}}, location = {{Nara (Japan)}}, pages = {{291--294}}, publisher = {{Elsevier BV}}, title = {{{Growth of cubic GaN on 3C–SiC/Si (001) nanostructures}}}, doi = {{10.1016/j.jcrysgro.2012.10.011}}, volume = {{378}}, year = {{2012}}, } @article{4136, abstract = {{Results of atomistic simulations aimed at understanding precipitation of the highly attractive wide band gap semiconductor material silicon carbide in silicon are presented. The study involves a systematic investigation of intrinsic and carbon-related defects as well as defect combinations and defect migration by both, quantummechanical first-principles as well as empirical potential methods. Comparing formation and activation energies, ground-state structures of defects and defect combinations as well as energetically favorable agglomeration of defects are predicted. Moreover, accurate ab initio calculations unveil limitations of the analytical method based on a Tersoff-like bond order potential. A work-around is proposed in order to subsequently apply the highly efficient technique on large structures not accessible by first-principles methods. The outcome of both types of simulation provides a basic microscopic understanding of defect formation and structural evolution particularly at non-equilibrium conditions strongly deviated from the ground state as commonly found in SiC growth processes. A possible precipitation mechanism, which conforms well to experimental findings and clarifies contradictory views present in the literature is outlined.}}, author = {{Zirkelbach, F. and Stritzker, B. and Nordlund, K. and Schmidt, Wolf Gero and Rauls, E. and Lindner, Jörg K. N.}}, issn = {{1862-6351}}, journal = {{physica status solidi (c)}}, number = {{10-11}}, pages = {{1968--1973}}, publisher = {{Wiley}}, title = {{{First-principles and empirical potential simulation study of intrinsic and carbon-related defects in silicon}}}, doi = {{10.1002/pssc.201200198}}, volume = {{9}}, year = {{2012}}, } @article{4140, abstract = {{In this paper we report on the successful reduction of tensile strain in a thin strained ion-beam synthesized 3C-SiC(1 1 1) layer on silicon. The creation of a near-interface defect structure consisting of nanometric voids and stacking fault type defects by He ion implantation and subsequent annealing yields significant relaxation in the top SiC film. The microstructure of the defect layer is studied by transmission electron microscopy, and the strain state of the 3C-SiC layer was studied by high-resolution X-ray diffraction in a parallel beam configuration. Typical process conditions for the growth of GaN films on the SiC layer were emulated by high temperature treatments in a rapid thermal annealer or a quartz tube furnace. It is found that prolonged annealing at high temperatures leads to ripening of the voids and to a weaker reduction of the tensile strain. It is shown that this problem can be overcome by the co-implantation of oxygen ions to form highly thermally stable void/extended defect structures.}}, author = {{Häberlen, M. and Murphy, B. and Stritzker, B. and Lindner, Jörg}}, issn = {{0168-583X}}, journal = {{Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms}}, pages = {{322--325}}, publisher = {{Elsevier BV}}, title = {{{Relaxation of a strained 3C-SiC(111) thin film on silicon by He+ and O+ ion beam defect engineering}}}, doi = {{10.1016/j.nimb.2011.01.092}}, volume = {{272}}, year = {{2011}}, } @article{4142, abstract = {{This paper reports the successful reduction of tensile strain in a thin ion-beam-synthesized 3C-SiC(111) layer on silicon. Significant relaxation is achieved by creating a near-interface defect structure containing nanometric voids and dislocation loops by the implantation of He ions and subsequent thermal annealing. The structural features of this defect microstructure are investigated by transmission electron microscopy. High-resolution X-ray diffraction in a parallel beam configuration is used to quantify the strain state of the top SiC layer. Further annealing experiments were carried out in order to emulate typical process conditions for the growth of wide-bandgap semiconductors like, for example GaN. It is found that prolonged annealing at elevated temperatures leads to coarsening of the voids and to a much less efficient strain reduction. We show that this issue can be resolved by the co-implantation of oxygen to form highly thermally stable cavity/extended defect structures. The technique presented here may be useful for a variety of other thermally mismatched bulk/thin film couples as well.}}, author = {{Häberlen, Maik and Murphy, Brian and Stritzker, Bernd and Lindner, Jörg}}, issn = {{1862-6351}}, journal = {{physica status solidi (c)}}, number = {{3}}, pages = {{944--947}}, publisher = {{Wiley}}, title = {{{Decoupling of a strained 3C-SiC(111) thin film on silicon by He+ and O+ ion implantation}}}, doi = {{10.1002/pssc.201000342}}, volume = {{8}}, year = {{2011}}, } @article{4148, abstract = {{Photoluminescence spectra of Sm^(2+)-doped BaBr^2 have been measured under hydrostatic pressures up to 17 GPa at room temperature. In the low pressure range a red-shift of the broad 5d–4f transition of -145 cm^(-1)/GPa is observed. From 5 to 8 GPa a phase mixtureof the initial orthorhombic phase and the high-pressure monoclinic phase gives rise to two 5d–4f bands, which are strongly overlapping. Above 8 GPa the crystalis completely transformed to its high-pressure phase where two different Sm2^(2+) sites exist, but only one broad 5d–4f transition is detected. It exhibits are d-shift of -36 cm^(-1)/GPa. In addition,the line shifts of the (_^5)D_0→(_^7)F_J (J=0,1,2) transitions are investigated. Linear shifts of -19cm^(-1)/GPa for J=0,2 and of -13cm^(-1)/GPa for J01 are observed in the pressure range from 0 to 5 GPa.}}, author = {{Wiegand, Marie Christin and Sievers, Werner and Lindner, Jörg and Tröster, Th. and Schweizer, S.}}, issn = {{0022-2313}}, journal = {{Journal of Luminescence}}, number = {{11}}, pages = {{2400--2403}}, publisher = {{Elsevier BV}}, title = {{{Photoluminescence properties of Sm2+-doped BaBr2 under hydrostatic pressure}}}, doi = {{10.1016/j.jlumin.2011.05.035}}, volume = {{131}}, year = {{2011}}, } @article{4150, abstract = {{Atomistic simulations on the silicon carbide precipitation in bulk silicon employing both, classical potential and first-principlesmethods are presented. The calculations aim at a comprehensive,microscopic understanding of the precipitation mechanism in the context of controversial discussions in the literature. For the quantum-mechanical treatment, basic processes assumed in the precipitation process are calculated in feasible systems of small size. The migration mechanism of a carbon 100 interstitial and silicon 11 0 self-interstitial in otherwise defect-free silicon are investigated using density functional theory calculations. The influence of a nearby vacancy, another carbon interstitial and a substitutional defect as well as a silicon self-interstitial has been investigated systematically. Interactions of various combinations of defects have been characterized including a couple of selected migration pathways within these configurations. Most of the investigated pairs of defects tend to agglomerate allowing for a reduction in strain. The formation of structures involving strong carbon–carbon bonds turns out to be very unlikely. In contrast, substitutional carbon occurs in all probability. A long range capture radius has been observed for pairs of interstitial carbon as well as interstitial carbon and vacancies. A rather small capture radius is predicted for substitutional carbon and silicon self-interstitials. Initial assumptions regarding the precipitation mechanism of silicon carbide in bulk silicon are established and conformability to experimental findings is discussed. Furthermore, results of the accurate first-principles calculations on defects and carbon diffusion in silicon are compared to results of classical potential simulations revealing significant limitations of the latter method. An approach to work around this problem is proposed. Finally, results of the classical potential molecular dynamics simulations of large systems are examined, which reinforce previous assumptions and give further insight into basic processes involved in the silicon carbide transition.}}, author = {{Zirkelbach, F. and Stritzker, B. and Nordlund, K. and Lindner, Jörg and Schmidt, W. G. and Rauls, E.}}, issn = {{1098-0121}}, journal = {{Physical Review B}}, number = {{6}}, publisher = {{American Physical Society (APS)}}, title = {{{Combinedab initioand classical potential simulation study on silicon carbide precipitation in silicon}}}, doi = {{10.1103/physrevb.84.064126}}, volume = {{84}}, year = {{2011}}, }