Search results for "Mesoscopic System"
showing 10 items of 587 documents
Quantifying the inverse spin-Hall effect in highly doped PEDOT:PSS
2020
The authors provide experimental results that show the onset of the Nernst effect, thermovoltages and an inverse spin-Hall effect in the polymer PEDOT:PSS. Specifically, the observed inverse spin-Hall effect appears to be smaller than other measurements, but in better agreement with theoretical calculations.
Numerical model for composite material with polymer matrix reinforced by carbon nanotubes
2008
Due to the high stiffness and strength, as well as their ability to act as conductors, carbon nanotubes are under intense investigation as fillers in polymeric materials. The nature of the carbon nanotube/polymer bonding and the curvature of the carbon nanotubes within the polymer have arisen as particular factors in the efficacy of the carbon nanotubes to actually provide any enhanced stiffness or strength to the nanocomposite. Here the effects of carbon nanotube curvature and interface interaction with the matrix on the nanocomposite stiffness are investigated using nanomechanical analysis. In particular, the effects of poor bonding and thus poor shear lag load transfer to the carbon nano…
Photoluminescence waveguiding in CdSe and CdTe QDs–PMMA nanocomposite films
2011
In this paper, active planar waveguides based on the incorporation of CdSe and CdTe nanocrystal quantum dots in a polymer matrix are demonstrated. In the case of doping the polymer with both types of quantum dots, the nanocomposite film guides both emitted colors, green (550 nm, CdTe) and orange (600 nm, CdSe). The optical pumping laser can be coupled not only with a standard end-fire coupling system, but also directing the beam to the surface of the sample, indicating a good absorption cross-section and waveguide properties. To achieve these results, a study of the nanocomposite optical properties as a function of the nanocrystal concentration is presented and the optimum conditions are fo…
Crystal structure and Hirshfeld surface analysis of (E)-3-(benzylideneamino)-5-phenylthiazolidin-2-iminium bromide
2020
The central thiazolidine ring of the title salt, C16H16N3S+center dot Br-, adopts an envelope conformation, with the C atom bearing the phenyl ring as the flap atom. In the crystal, the cations and anions are linked by N-H center dot center dot center dot Br hydrogen bonds, forming chains parallel to the b-axis direction. Hirshfeld surface analysis and two-dimensional fingerprint plots indicate that the most important contributions to the crystal packing are from H center dot center dot center dot H (46.4%), C center dot center dot center dot H/H center dot center dot center dot C (18.6%) and H center dot center dot center dot Br/Br center dot center dot center dot H (17.5%) interactions.
Exciton and multiexciton optical properties of single InAs/GaAs site-controlled quantum dots
2013
We have studied the optical properties of InAs site-controlled quantum dots (SCQDs) grown on pre-patterned GaAs substrates. Since InAs nucleates preferentially on the lithography motifs, the location of the resulting QDs is determined by the pattern, which is fabricated by local oxidation nanolithography. Optical characterization has been performed on such SCQDs to study the fundamental and excited states. At the ground state different exciton complex transitions of about 500 μeV linewidth have been identified and the fine structure splitting of the neutral exciton has been determined (≈65 μeV). The observed electronic structure covers the demands of future quantum information technologies.…
Crystal structure and Hirshfeld surface analysis of (E)-1-[2,2-dichloro-1-(4-nitrophenyl)ethenyl]-2-(4-fluorophenyl)diazene
2019
The dihedral angle between the 4-fluorophenyl ring and the nitro-substituted benzene ring of the title compound is 63.29 (8)°. In the crystal, molecules are linked by C—H⋯O hydrogen bonds into chains parallel to the c axis. The crystal packing is further stabilized by C—Cl⋯π, C—F⋯π and N—O⋯π interactions
Crystal structure and Hirshfeld surface analysis of 2-[(1,3-benzoxazol-2-yl)sulfanyl]-N-(2-methoxyphenyl)acetamide
2019
Akkurt, Mehmet/0000-0003-2421-0929; Saylam, Merve/0000-0002-7602-4565
Crystal structure and Hirshfeld surface analysis of (E)-3-[(4-fluorobenzylidene)amino]-5-phenylthiazolidin-2-iminium bromide
2019
TARAMAPUBMED TARAMASCOPUS TARAMAWOS In the cation of the title salt, C16H15FN3S+·Br−, the phenyl ring is disordered over two sets of sites with a refined occupancy ratio of 0.503 (4):0.497 (4). The mean plane of the thiazolidine ring makes dihedral angles of 13.51 (14), 48.6 (3) and 76.5 (3)° with the fluorophenyl ring and the major- and minor-disorder components of the phenyl ring, respectively. The central thiazolidine ring adopts an envelope conformation. In the crystal, centrosymmetrically related cations and anions are linked into dimeric units via N—H...Br hydrogen bonds, which are further connected by weak C—H...Br hydrogen bonds into chains parallel to [110]. Hirshfeld surface an…
Two‐Dimensional Electron Gas Effects on the Photoluminescence from a Nonintentionally Doped AlGaN/GaN Heterojunction
2002
Photoluminescence measurements on an AlGaN/GaN single heterojunction (SH), where piezoelectric and spontaneous polarization effects confine a two-dimensional electron gas (2DEG), are presented. Well-defined emissions between the bulk excitonic transitions and their LO-phonon replica are attributed to spatially indirect excitons located close to the interface. The strong interfacial electric field separates photogenerated holes and electrons, weakening their Coulomb interaction and causing a blueshift with increasing excitation intensity due to carrier population effects. In addition, direct experimental proof is obtained by applying an electric field normal to the interface. An energy shift…
A Composite Phononic Crystal Design for Quasiparticle Lifetime Enhancement in Kinetic Inductance Detectors
2020
A nanoscale phononic crystal filter (reflector) is designed for a kinetic inductance detector where the reflection band is matched to the quasiparticle recombination phonons with the aim to increase quasiparticle lifetime in the superconducting resonator. The inductor is enclosed by a 1-μm-wide phononic crystal membrane section with two simple hole patterns that each contain a partial spectral gap for various high-frequency phonon modes. The phononic crystal is narrow enough for low-frequency thermal phonons to propagate unimpeded. With 3D phonon scattering simulation over a 40 dB attenuation in transmitted power is found for the crystal, which is estimated to give a lifetime enhancement of…