Sebastian B. C. Lehmann

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In this study we present the results of a first principles molecular dynamics simulation of a single 1-ethyl-3-methyl-imidazolium chloride [C(2)C(1)im][Cl] ion pair dissolved in 60 water molecules. We observe a preference of the in plane chloride coordination with respect to the cation ring plane as compared to the energetic slightly more demanding on top(More)
III−V Nanowires (NWs) grown with metal−organic chemical vapor deposition commonly show a polytypic crystal structure, allowing growth of structures not found in the bulk counterpart. In this paper we studied the radial overgrowth of pure wurtzite (WZ) GaAs nanowires and characterized the samples with high resolution X-ray diffraction (XRD) to reveal the(More)
We determine the detailed differences in geometry and band structure between wurtzite (Wz) and zinc blende (Zb) InAs nanowire (NW) surfaces using scanning tunneling microscopy/spectroscopy and photoemission electron microscopy. By establishing unreconstructed and defect-free surface facets for both Wz and Zb, we can reliably measure differences between(More)
Controlled formation of non-equilibrium crystal structures is one of the most important challenges in crystal growth. Catalytically grown nanowires are ideal systems for studying the fundamental physics of phase selection, and could lead to new electronic applications based on the engineering of crystal phases. Here we image gallium arsenide (GaAs)(More)
Semiconducting indium sulfide (In2S3) has recently attracted considerable attention as a buffer material in the field of thin film photovoltaics. Compared with this growing interest, however, detailed characterizations of the crystal structure of this material are rather scarce and controversial. In order to close this gap, we have carried out a(More)
Reliable wet-chemical cleaning of natively oxidized high-efficiency Cu(In,Ga)Se 2 thin-film solar cell absorbers, in extratropical storm tracks and baroclinicity under climate change, Environ. Res. The role of the North Atlantic overturning and deep ocean for multi-decadal global-mean-temperature variability, Earth Syst.
The widespread use of Au as a seed particle in the fabrication of semiconductor nanowires presents a fundamental limitation to the potential incorporation of such nanostructures into electronic devices. Although several other growth techniques have been demonstrated, the use of alternative seed particle metals remains an underexplored but potentially very(More)
Radiative recombination in degenerately n-doped InP nanowires is studied for excitation above and below the Fermi energy of the electron gas, using photoluminescence. Laser-induced electron heating is observed, which allows absorption below the Fermi energy. We observe photon upconversion where photo-excited holes recombine with high |k| electrons. This can(More)
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