Instead of investigating the quantum effect that influences the absorption band edge of TiO2 nanostructures, herein we report that geometrical parameters can also be utilized to manipulate the optical band gap of the TiO2 nanotube arrays. Hexagonal arrays of TiO2 nanotubes with an excellent crystalline quality were fabricated by techniques combining anodic aluminum oxide templates and atomic la...

Rutile TiO2 (110) single crystals were doped with nitrogen by heating at 675 C in flowing NH3 gas. This caused a red shift in the band edge and an increase in visible region absorption. Nitrogen depth profiles obtained using dynamic secondary ion mass spectrometry (SIMS) could best be fitted by assigning three distinct diffusion coefficients. X-Ray photoelectron spectroscopy (XPS) indicated the...

Strain-dependent structural and electronic properties of MoS2 materials are investigated using first principles calculations. The structural and electronic band structures of the MoS2 with relaxed unit cells are optimized and calculated by the dispersion-corrected density functional theory (DFT-D2). Calculations within the local density approximation (LDA) and GGA using PAW potentials were also...

We argue, based on band structure calculations and the Eliashberg theory, that the observed decrease of T(c) of Al and C doped MgB2 samples can be understood mainly in terms of a band filling effect due to the electron doping by Al and C. A simple scaling of the electron-phonon coupling constant lambda by the variation of the density of states as a function of electron doping is sufficient to c...

The Atmospheric Pressure Chemical Vapor Synthesis (APCVS) route is a process that can be used for the synthesis of doped-nanocrystalline powders with very small crystallite sizes having a narrow particle size distribution and high purity. In this study, APCVS technique was used to prepare boron-doped titania nanopowders. The effects of temperature, borate flow rate and water flow rate on the am...

We report the observation of large (approximately 40%) laser-induced above-band-gap transparency in GaAs at room temperature. The induced transparency is present only during the pulse width of the driving midinfrared laser pulses and its spectral shape is consistent with a laser-induced blueshift of the band edge. Our simulations based on the dynamic Franz-Keldysh effect reproduce the salient f...

nanoparticles of zirconium(iv) tungstate are prepared by chemical co-precipitation method. thecharacterizations have been carried out by tg/dta, dsc, afm, xrd, ftir and uv-vis spectrum. plspectrum shows two emission bands at 350 nm and at 477 nm. the effects of frequency on the dielectricbehavior and ac electrical conductivity have been studied. the dielectric constant is found to be 119.43 at1...

The aim of this paper is to study the effect of Mn concentration on the structural, magneticand optical properties of TiO2 nanoparticles. TiO2 nanopowders with Mn concentration of 0%,0.2%, 1% and 5% were synthesized by the sol-gel method. The structural, surface morphologyand average crystal grain size, optical, magnetic properties and chemical compounds of thesamples are studied using XRD, FE-...

The luminescence of semiconductor nanostructures is strongly dependent on their size, dimensions, morphology, composition, or defects, and their band emissions can be properly and selectively tailored through the rational manipulation of these parameters during material growth. Using spatially-resolved cathodoluminescence spectroscopy, monochromatic contrast maps and high-resolution transmissio...

Cadmium Sulphide (CdS) nanoparticles were prepared using microemulsion method using cadmium chloride as cadmium source and sodium sulphide as sulphur source. The obtained nanoparticles structures were characterized by X-ray diffraction (XRD) and Transmission Electron Microscopy (TEM) whereas optical characterization was done by Ultra Violet-Visible absorption. XRD result shows that CdS nanopart...