Browsing by Keywords "Energy gap"
Now showing items 1-20 of 58
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Ab initio study of Ru-terminated and Ru-doped armchair graphene nanoribbons
(Taylor and Francis, 2012)We investigate the effects of ruthenium (Ru) termination and Ru doping on the electronic properties of armchair graphene nanoribbons (AGNRs) using first-principles methods. The electronic band structures, geometries, density ... -
Accurate method for obtaining band gaps in conducting polymers using a DFT/hybrid approach
(American Chemical Society, 1998)DFT calculations on a series of oligomers have been used to estimate band gaps, ionization potentials, electron affinities, and bandwidths for polyacetylene, polythiophene, polypyrrole, polythiazole, and a thiophene - ... -
All-chalcogenide glass omnidirectional photonic band gap variable infrared filters
(AIP Publishing, 2009)We report on the design, fabrication, and characterization of spatially variable infrared photonic band gap filter that consists of thermally evaporated, high refractive indexcontrast, amorphous chalcogenide glass multilayers. ... -
All-chalcogenide variable infrared filter
(SPIE, 2009)We present the design, fabrication, characterization of spatially variable infrared filter and a demonstration of the filter as a simple infrared spectrometer. A varying photonic band gap filter which consists of thermally ... -
Band gap and optical transmission in the Fibonacci type one-dimensional A5B6C7 based photonic crystals
(Wiley-VCH Verlag, 2015)In this work, we present an investigation of the optical properties and band structure calculations for the photonic crystal structures (PCs) based on one-dimensional (1D) photonic crystal. Here we use 1D A5B6C7(A:Sb; ... -
Band gap structure of elliptic rods in water for a 2D phononic crystal
(Springer Verlag, 2017)The propagation of acoustic waves in two-dimensional sonic crystals (SC) is studied theoretically. Effects of elliptical rod orientations on the acoustic band gaps in periodic arrays of rigid solid rods embedded in a polar ... -
Band Structure and Optical Properties of Kesterite Type Compounds: First principle calculations
(Institute of Physics Publishing, 2017)In present work, our research is mainly focused on the electronic structures, optical and magnetic properties of Cu2FeSnZ4 (Z = S, Se) compounds by using ab initio calculations within the generalized gradient approximation ... -
Bio-insprired optoelectronic digital nose for breath analysis
(2011)A novel electronic nose device is presented that can be used in disease diagnostics by exhaled breath analysis. Exhaled breath contains more than a thousand organic compounds that can be analysed to insect various diseases ... -
Confined optical phonon effects on the band gap renormalization in quantum wire structures
(Elsevier Science, 1999)We consider the different approximations for the bandgap renormalization (BGR) within the random phase approximation (RPA), the quasi-static limit and the plasmon-pole approximation, and compare with the full result. We ... -
Coupled optical microcavities in one-dimensional photonic bandgap structures
(Institute of Physics Publishing, 2001)We present a detailed theoretical and experimental study of the evanescent coupled optical microcavity modes in one-dimensional photonic bandgap structures. The coupled-cavity samples are fabricated by depositing alternating ... -
Density functional theory investigation of substituent effects on building blocks of conducting polymers
(Elsevier, 1999)Substituted heterocyclic dimers were calculated employing density functional theory (DFT) and analyzed with the natural bond orbits method (NBO). Substitution in 3- and 4-positions leads to parallel shifting of HOMO and ... -
Dynamic nonlinear optical processes in some oxygen-octahedra ferroelectrics: first principle calculations
(Taylor & Francis Inc., 2015)The nonlinear optical properties and electro-optic effects of some oxygen-octahedra ferroelectrics are studied by the density functional theory (DFT) in the local density approximation (LDA) expressions based on first ... -
Effect of chalcogens on electronic and photophysical properties of vinylene-based diketopyrrolopyrrole copolymers
(American Chemical Society, 2015)Three vinylene linked diketopyrrolopyrrole based donor−acceptor (D−A) copolymers have been synthesized with phenyl, thienyl, and selenyl units as donors. Optical and electronic properties were investigated with UV−vis ... -
Effect of reactor pressure on optical and electrical properties of InN films grown by high-pressure chemical vapor deposition
(Wiley - V C H Verlag GmbH & Co. KGaA, 2015)The influences of reactor pressure on the stoichiometry, free carrier concentration, IR and Hall determined mobility, effective optical band edge, and optical phonon modes of HPCVD grown InN films have been analysed and ... -
Effects of perfluorination on thiophene and pyrrole oligomers
(2010)The effect of perfluorination on thiophene and pyrrole oligomers in neutral, cationic, and anionic states was investigated with density functional theory at the (TD)B3P86-30%/6-31G* level. For the title compounds fluorination ... -
Electronic structure of half-metallic ferromagnet Co2MnSi at high-pressure
(Springer New York LLC, 2010)In this study, first principles calculation results of the half-metallic ferromagnetic Heusler compound Co2MnSi are presented. All calculations are based on the spin-polarized generalized gradient approximation (σ-GGA) of ... -
Enhancement of optical switching parameter and third-order optical nonlinearities in embedded Si nanocrystals: A theoretical assessment
(Elsevier, 2008)Third-order bound-charge electronic nonlinearities of Si nanocrystals (NCs) embedded in a wide band-gap matrix representing silica are theoretically studied using an atomistic pseudopotential approach. Nonlinear refractive ... -
Experimental demonstration of highly confined photonic crystal based waveguides
(IEEE, 2001)The bending and guiding of the electromagnetic (EM) waves in highly confined waveguides was demonstrated. The electromagnetic waves were constructed by removing a single rod from a perfect three layer-by-layer photonic ... -
Experimental investigation of layer-by-layer metallic photonic crystals
(Institution of Electrical Engineers, 1998-12)The authors have investigated the transmission properties and defect characteristics of layer-by-layer metallic photonic crystals. They have demonstrated experimentally that the metallicity gap of these crystals extends ... -
Fundamentals, progress, and future directions of nitride-based semiconductors and their composites in two-dimensional limit: a first-principles perspective to recent synthesis
(American Institute of Physics Inc., 2018)Potential applications of bulk GaN and AlN crystals have made possible single and multilayer allotropes of these III-V compounds to be a focus of interest recently. As of 2005, the theoretical studies have predicted that ...
