Using density functional theory, the G0W0 method and Bethe-Salpeter equation calculations, we systematically explore the structural, electronic and optical properties of hydrogenated and fluorinated germanene. The hydrogenated/fluorinated germanene tends to form chair and zigzag-line configurations and its electronic and optical properties show close geometry dependence. The chair hydrogenated/...

Experiments are described on the prism-coupled excitation of surface electromagnetic waves in one-dimensional photonic band-gap arrays. The low loss of photonic band-gap materials leads to narrow angular reflectivity resonances and high surface fields. These attributes, coupled with the ability to engineer the optical properties of photonic band-gap arrays, suggest these materials as powerful r...

ZnO thin films with preferred orientation along the (002) plane were prepared onto the glass substrates by the sol-gel spin coating method for different post- annealing temperatures. The XRD study confirms that the thin films grown by this method have good crystalline hexagonal wurtzite structure. The optical band gap of the samples was determined from UV-visible spectra. It is found that the s...

Amorphous C/diamond films have been prepared by rf plasma enhanced vapor deposition from a CHdAr gas mixture. Infrared and optical-ultraviolet absorption characteristics are reported and used to characterize the bonding and optical properties of these films. It has been found that the optical band gap is not related to the hydrogen content in the films and varies according to the dc self bias d...

Localization of matter waves in optical lattices is possible due to the balance of nonlinearity and dispersion which is modified by the band-gap spectrum of matter waves in a periodic potential. Nonlinear localization of a Bose-Einstein condensate with repulsive interatomic interactions loaded into a onedimensional (1D) optical lattice can occur in the form of both bright and dark solitons. Dar...

Abstract. Band structure and optical properties of defectChalcopyrite type semiconductor ZnIn2Te4 have been studied by TB-LMTO first principle technique. The optical absorption calculation suggest that ZnIn2Te4 is a direct-gap semiconductor having a band gap of 1.40 eV., which confirms the experimentally measured value. The calculated complex dielectric-function ǫ(E) = ǫ1(E)+ iǫ2(E) reveal dist...

We demonstrate theoretically that it is possible to realize terahertz (THz) fundamental band-gap between the electron mini-band in the InAs layer and the heavy-hole mini-band in the GaSb layer in InAs/GaSb based type II superlattices (SLs). The THz band-gap can be tuned by varying the sample growth parameters such as the well widths of the InAs and/or GaSb layers. The presence of such band-gap ...

The samples of CR-39 polymer (TASTRAK, Bristol, England) were annealled thermally at various temperatures ranging from 100oC to 180oC for 1 hour, in air. FTIR spectroscopy reveals the structural degradation of CR-39 polymer due to thermal annealing above its glass transition temperature. Optical band gap of pristine and thermally annealed samples has been determined using UV-Visible absorption ...

ZnO thin films with preferred orientation along the (002) plane were prepared onto the glass substrates by the sol-gel spin coating method for different post- annealing temperatures. The XRD study confirms that the thin films grown by this method have good crystalline hexagonal wurtzite structure. The optical band gap of the samples was determined from UV-visible spectra. It is found that the s...

in this study we investigate the effect of atoms such as b, n, ge and sn on the optical and the electrical properties of capped (5, 0) zigzag carbon nanotube, using dft calculation method. these elements were attached to the one end of the carbon nanotube. we considered four different structure designs as possible candidates for a p-n junction device. the electrical properties of these structur...