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Showing papers by "Anvar A. Zakhidov published in 2006"


Patent
13 Oct 2006
TL;DR: In this paper, the authors present a process for the combination of injecting charge in a material electrochemically via non-faradaic (double-layer) charging, and retaining this charge and associated desirable properties changes when the electrolyte is removed.
Abstract: In some embodiments, the present invention is directed to processes for the combination of injecting charge in a material electrochemically via non-faradaic (double-layer) charging, and retaining this charge and associated desirable properties changes when the electrolyte is removed. The present invention is also directed to compositions and applications using material property changes that are induced electrochemically by double-layer charging and retained during subsequent electrolyte removal. In some embodiments, the present invention provides reversible processes for electrochemically injecting charge into material that is not in direct contact with an electrolyte. Additionally, in some embodiments, the present invention is directed to devices and other material applications that use properties changes resulting from reversible electrochemical charge injection in the absence of an electrolyte.

102 citations


Journal ArticleDOI
TL;DR: In this paper, the effect of negative refraction in homogeneous isotropic chiral media in a nonresonant frequency domain close to the frequency of longitudinal excitations was investigated.
Abstract: The gyrotropy (chirality) as one of the manifestations of spatial dispersion responsible, e.g., for the rotation of the plane of polarization of light can also lead to negative refraction (NR) in certain frequency ranges. We discuss this effect for homogeneous isotropic chiral media in a nonresonant frequency domain close to frequency ${\ensuremath{\omega}}_{L}$ of longitudinal excitations, where dielectric permittivity vanishes: $ϵ({\ensuremath{\omega}}_{L})=0$. Basic phenomena of reflection and refraction at the boundary of a chiral medium are considered and NR is demonstrated for frequencies below ${\ensuremath{\omega}}_{L}$ as following from the negative group velocity of circularly polarized electromagnetic waves of one handedness. We show that specular reflection of the polarized waves should provide a means of direct experimental detection of this frequency domain. We also discuss dissipation-related limitations for realization of NR.

50 citations


Journal ArticleDOI
TL;DR: In this paper, an oriented, strong and transparent multiwall carbon nanotube sheet is used as the hole collecting electrode in polymer solar cells with RR-P3HT as the donor material and PCBM as the acceptor material.
Abstract: In this study, an oriented, strong and transparent multiwall carbon nanotube sheet is used as the hole collecting electrode in polymer solar cells with RR-P3HT as the donor material and PCBM as the acceptor material. An open circuit voltage of 0.49 V, a short circuit current of 5.47 mA/cm 2 , a fill factor of 0.49, and an efficiency of 1.32% have been obtained. Performance dependence on incident light intensity along with other various investigations are presented.

34 citations


Journal ArticleDOI
TL;DR: In this paper, large surface infrared photonic crystals with reflectance higher than 90% have been synthesized by self-assembling large size SiO2 spheres, of 0.8 - 4.5 m diameters, followed by melt infiltration with the chalcogenide glass Ge33As12Se55 and the removal of the SiO 2 spheres by chemical etching.
Abstract: Large surface infrared photonic crystals with reflectance higher than 90% have successfully been synthesized by self-assembling large size SiO2 spheres, of 0.8 - 4.5 m diameters, followed by melt infiltration with the chalcogenide glass Ge33As12Se55 and the removal of the SiO2 spheres by chemical etching. The sphere size and the periodicity of the templates were chosen to guarantee the formation of photonic band gaps of the inverted opals in the targeted IR regions of 3-5 m and 8-12 m. Fabrication, structural features and spectral behavior of the reflectance peaks of these chalcogenide glass inverse opals are presented.

22 citations


Journal ArticleDOI
TL;DR: In this article, the Raman spectra of single-wall nanotubes under high pressure combined with shear deformation were investigated in situ in a diamond cell, and the hardness of the superhard material was 58±6 GPa.
Abstract: Raman spectra of single-wall nanotubes under high pressure combined with shear deformation are investigated in situ in a diamond cell. Shear deformation applied under 35 GPa led to pressure multiplication up to 60 GPa, and increased the intensity of Raman bands more than ten times without essential change of G-mode position while causing its essential broadening. The G-mode remained broad after pressure unloading and shifted to 1534 cm −1 . The hardness of the superhard material was 58±6 GPa, comparable to the hardness of carbo-boro-nitride. A broad band appeared in the photoluminescence spectrum with a maximum at about 2 eV, which allowed to assume a high content of sp 3 -bonds in the sample. The large dispersion of the G-mode almost vanished after pressure unloading. However, a noticeable dispersion of the D-mode was found, which is a sign of certain ordering in the superhard phase. TEM study of the superhard phase detected clusters with graphene sheets with a size about 1 nm.

16 citations



Journal ArticleDOI
TL;DR: By reduction of SiO2 opal in atmosphere of nitrogen (80%)-helium (15%)-hydrogen (5%) gas mixture at various temperatures, this paper tuned the dielectric contrast ratio and band gap of photonic crystal (PC) up to 10 %.
Abstract: By reduction of SiO2 opal in atmosphere of nitrogen (80%)-helium (15%)-hydrogen (5%) gas mixture at various temperatures we tuned the dielectric contrast ratio and band gap of photonic crystal (PC) up to 10 %. The SEM images dose not show any detectible change in lattice parameters, whereas the elemental analysis shows remarkable decrease of oxygen content. The shift of reflectance spectra toward the long wavelength and increase of transmission in infrared region confirm the redaction of silica and partial transformation to the silicon.

Journal ArticleDOI
TL;DR: In this article, laser flash and self-heating 3ω techniques were employed to determine the anisotropic thermal conductivity and thermal diffusivity of highly oriented free standing multiwalled carbon nanotube (MWNT) sheet drawn from a sidewall of a MWNT forest that was grown by chemical-vapor deposition.
Abstract: Laser flash and self-heating 3ω techniques were employed to determine the anisotropic thermal conductivity and thermal diffusivity of highly oriented free standing multiwalled carbon nanotube (MWNT) sheet drawn from a sidewall of a MWNT forest that was grown by chemical-vapor deposition. The thermal conductivity and the thermal diffusivity along the alignment are 50±5 W/m·K and 45±5 mm2/s, respectively, and are mostly limited by intrinsic defects of individual nanotubes and phonon-phonon interaction within bundles which form the supporting matrix of the MWNT sheet. The long tube-tube overlapping substantially decreases the electrical and thermal interconnection resistances which are usually dominate in randomly deposited mat-like nanotube assemblies. The extremely large surface area of the MWNT sheet leads to excessive heat radiation that dose not allow to transfer the heat energy by means of phonons to distances > 2 mm.