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   Line shape of the Raman 2D peak of graphene in van der Waals heterostructures; ; et al in Physica Status Solidi B. Basic Research (2016), 253(12), 2326--2330 Detailed reference viewed: 115 (0 UL) Cu–Zn disorder and band gap fluctuations in Cu2ZnSn(S,Se)4: Theoretical and experimental investigations; Larsen, Jes K.  ; et alin Physica Status Solidi B. Basic Research (2016), 253(2), 247-254 Detailed reference viewed: 179 (1 UL)Raman spectroscopy of graphite intercalation compounds: Charge transfer, strain, and electron–phonon coupling in graphene layers; Wirtz, Ludger ; in Physica Status Solidi B. Basic Research (2014), 251(12), 23372355 Graphite intercalation compounds (GICs) are an interesting and highly studied field since 1970’s. It has gained renewed interest since the discovery of superconductivity at high temperature for CaC6 and ... [more ▼] Graphite intercalation compounds (GICs) are an interesting and highly studied field since 1970’s. It has gained renewed interest since the discovery of superconductivity at high temperature for CaC6 and the rise of graphene. Intercalation is a technique used to introduce atoms or molecules into the structure of a host material. Intercalation of alkali metals in graphite has shown to be a controllable procedure recently used as a scalable technique for bulk production of graphene, and nano-ribbons by induced exfoliation of graphite. It also creates supra-molecular interactions between the host and the intercalant, inducing changes in the electronic, mechanical, and physical properties of the host. GICs are the mother system of intercalation also employed in fullerenes, carbon nanotubes, graphene, and carbon-composites. We will show how a combination of Raman and ab-initio calculations of the density and the electronic band structure in GICs can serve as a tool to elucidate the electronic structure, electron–phonon coupling, charge transfer, and lattice parameters of GICs and the graphene layers within. This knowledge of GICs is of high importance to understand superconductivity and to set the basis for applications with GICs, graphene and other nano-carbon based materials like nanocomposites in batteries and nanoelectronic devices. [less ▲] Detailed reference viewed: 239 (11 UL)Raman spectroscopy on mechanically exfoliated pristine graphene ribbons; Reichardt, Sven ; et alin Physica Status Solidi B. Basic Research (2014), 251(12), 2551--2555 Detailed reference viewed: 148 (3 UL)Impact of thermal annealing on graphene devices encapsulated in hexagonal boron nitride; ; et al in Physica Status Solidi B. Basic Research (2014), 251(12), 2545--2550 Detailed reference viewed: 143 (3 UL)Electronic structure and radial breathing mode for carbon nanotubes with ultra-high curvature; ; et al in Physica Status Solidi B. Basic Research (2010), 247(11-12), 2774-2778 Ultra-high curvature single-walled carbon nanotubes (SWCNTs) with diameters down to 0.37 nm were prepared by transformation of FeCp(2) peapods to double-walled CNTs (DWCNTs). Results from resonance Raman ... [more ▼] Ultra-high curvature single-walled carbon nanotubes (SWCNTs) with diameters down to 0.37 nm were prepared by transformation of FeCp(2) peapods to double-walled CNTs (DWCNTs). Results from resonance Raman scattering and high resolution transmission electron microscopy (TEM) were compared to calculations on the molecular dynamical, many electron corrected extended tight binding, and density functional theory (DFT) level. The growth process was found to be catalytic from Fe(3)C particles inside the tubes with dimensions of a crystallographic unit cell. The electronic structure showed dramatic deviations from tight binding results. The family behavior leads to level crossing already for E(11) and E(22) transitions. Experimental results fitted well into a Kataura-Popov plot and allowed assignment for the observed Raman lines of the inner tubes. Experimental and calculated radial breathing mode (RBM) frequencies showed a systematic difference indicating a radial expansion of the smallest inner tubes and a radial compression for the larger tubes. (c) 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim [less ▲] Detailed reference viewed: 125 (2 UL)New routes to sustainable photovoltaics: evaluation of Cu2ZnSnS4 as an alternative absorber material; Dale, Phillip ; et alin Physica Status Solidi B. Basic Research (2008), 245(9), 1772-1778 Detailed reference viewed: 155 (0 UL)Low energy quasiparticle dispersion of graphite by angle-resolved photoemission spectroscopy; ; et al in Physica Status Solidi B. Basic Research (2007), 244(11), 4129-4133 The low energy electron dispersion in graphite is measured by angle-resolved photoemission spectroscopy. The measured photoemission intensity maxima are compared to a tight-binding calculation of the ... [more ▼] The low energy electron dispersion in graphite is measured by angle-resolved photoemission spectroscopy. The measured photoemission intensity maxima are compared to a tight-binding calculation of the electronic band structure. We observe a strong trigonal warping of the equi-energy contour which is well reproduced by the calculations. Furthermore we clearly show that the concept of Dirac Fermions breaks down for AB stacked graphite. (c) 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. [less ▲] Detailed reference viewed: 120 (2 UL)Absorption of BN nanotubes under the influence of a perpendicular electric field; Wirtz, Ludger ; et alin Physica Status Solidi B. Basic Research (2007), 244(11), 4288-4292 We calculate the optical absorption spectra of prototype (6,6) and (9,9) BN nanotubes in the presence of a perpendicular electric field. This model mimics a gated BN nanotube device. Even though the band ... [more ▼] We calculate the optical absorption spectra of prototype (6,6) and (9,9) BN nanotubes in the presence of a perpendicular electric field. This model mimics a gated BN nanotube device. Even though the band-gap of the tubes decreases strongly as a function of the electric field strength, the absorption spectrum of the pure tubes remains remarkably constant up to high field-strength. We show that, in contrast, the levels which are responsible for defect-mediated photo-luminescence are shifted by the electric field. We address the use of BN nanotubes for optoelectronic applications. 0 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. [less ▲] Detailed reference viewed: 315 (1 UL)Carbon nanotubes in liquid crystals as versatile functional materials; Lagerwall, Jan ; et alin Physica Status Solidi B. Basic Research (2007), 244(11), 4212-4217 Liquid crystals can be easily aligned in desired directions by treated surfaces or by external fields. The least ordered liquid crystal phase, the nematic, exhibits orientational order that can be easily ... [more ▼] Liquid crystals can be easily aligned in desired directions by treated surfaces or by external fields. The least ordered liquid crystal phase, the nematic, exhibits orientational order that can be easily transferred onto carbon nanotubes dispersed in it. The alignment of the carbon nanotubes can be demonstrated by po- larized Raman spectroscopy. Carbon nanotubes not only well integrate in the matrix but also, even at very low concentration, have a detectable effect on the liquid crystal properties that can be very attractive for display applications. The presence of big aggregates of carbon nanotubes, on the other hand, interfere strongly with the switching behaviour of the liquid crystal, as we can show following the local switching of liquid crystal molecules with Raman spectroscopy. [less ▲] Detailed reference viewed: 153 (1 UL)Effect of phenyl rings in liquid crystal molecules on swcnts studied by raman spectroscopy; Lagerwall, Jan ; et alin Physica Status Solidi B. Basic Research (2006), 243(13), 3238-3241 Carbon nanotubes can be aligned by dispersing them in a liquid crystalline matrix. To control and opti- mize the obtained alignment it is important to understand the interactions between the molecules of ... [more ▼] Carbon nanotubes can be aligned by dispersing them in a liquid crystalline matrix. To control and opti- mize the obtained alignment it is important to understand the interactions between the molecules of the liquid crystal host phase and the carbon nanotubes. To this end we have carried out resonant Raman spec- troscopy investigations of dispersions of single-wall carbon nanotubes (SWCNTs) in a liquid crystal com- pound comprising molecules with a biphenyl rigid core structure. We detect a distinct wavenumber shift of the radial breathing modes, confirming that the carbon nanotubes interact with the surrounding liquid crystal molecules, most likely through aromatic interactions (π-stacking). The interactions between liquid crystal host and nanotube guests are also evident from a polarizing microscopy study of the liquid crys- tal – isotropic phase transition in the proximity of bundles of nanotubes. The ordered liquid crystal phase is stable up to higher temperatures around the bundles than in areas without visible signs of CNTs. Con- versely, the transition from the disordered isotropic phase to the liquid crystal phase on cooling always nucleates at the carbon nanotube bundles. [less ▲] Detailed reference viewed: 128 (0 UL)Simultaneous alignment and dispersion of carbon nanotubes with lyotropic liquid crystalsLagerwall, Jan ; ; et alin Physica Status Solidi B. Basic Research (2006), 243(13), 3046-3049 We demonstrate that single-wall carbon nanotubes (SWCNTs) can be macroscopically aligned by means of templating in a lyotropic nematic liquid crystal (LC), a self-assembling anisotropic fluid with orienta ... [more ▼] We demonstrate that single-wall carbon nanotubes (SWCNTs) can be macroscopically aligned by means of templating in a lyotropic nematic liquid crystal (LC), a self-assembling anisotropic fluid with orienta- tional but no translational order. The CNTs spontaneously adopt the alignment of the host, as we verify by means of resonant Raman spectroscopy. The aqueous LC host, based on the surfactant SDS, simultane- ously keeps the nanotubes well dispersed over time scales of months or longer. The LC can be loaded with CNTs to almost the same extent as the standard isotropic 1% surfactant solutions normally used for dispersing CNTs without any optically visible bundling occurring. [less ▲] Detailed reference viewed: 150 (0 UL) |
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