Water splitting for hydrogen production under sunlight using TiO2 as photo catalyst provides a better route for solar energy and attracts the attention of many researchers. The photo catalytic activity of TiO2 under sunlight irradiation depends on the band gap energy. The transition metal doped TiO2 shows an edge over TiO2 in optical absorbance and photo catalytic activity. Thin film of Cr dope...

In this work facile sol-gel (pechni) method has been successfully established to synthesize Zn4B6O13 nanocrystals which have cubic crystals with lattice parameter: a =7.48 A. The structure and morphology of the obtained material were studied by X-ray diffraction (XRD), Infrared spectra (IR), scanning electron microscopy (SEM) and photoluminescence analysis. The experimental results show a band ...

In this study, ZnO nanopowders and ZnO doped with metals (Cu , Ag- doped ZnO) and (Cd, Ag- doped ZnO) were synthesized by the sol-gel method in order to investigation on the codoping effect on the band gap and photocatalytic activity of ZnO. The synthesized samples are characterized by IR spectroscopy technique. Moreover, the absorption coefficients of the ZnO, Ag-Cd-ZnO and Ag-Cu-ZnO were anal...

In this paper, the properties of the defect mode in the photonic band gap ofone-dimensional ternary photonic crystals containing high temperature superconductorlayer (SPCs) have been theoretically investigated. We considered the quasi-periodiclayered structures by choosing two order of ternary Thue-Morse structures with mirrorsymmetry. We investigated the transmission spectra of these structure...

SiO2/ZnS core/shell nanostructures have been synthesized at room temperature by a simple wet chemical method. The prepared materials are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), infrared spectroscopy (IR), UV–vis spectroscopic and transmission electron microscopy (TEM) studies. X-ray diffraction pattern exhibits peaks correspond to the cubic phase of ZnS. Th...

Metamaterials have been the subject of significant interest over the past decade due to their ability to produce novel acoustic behaviour beyond that seen in naturally occurring media. As well as their potential in acoustic cloaks and lenses, of particular interest is the appearance of band gaps which lead to very high levels of attenuation across the material within narrow frequency ranges. Un...

We show that even in quantum-dot (QD) lasers with very low threshold current densities (Jth = 40–50 A/cm at 300 K), the temperature sensitivity of the threshold current arises from nonradiative recombination that comprises ∼60% to 70% of Jth at 300 K, whereas the radiative part of Jth is almost temperature insensitive. The influence of the nonradiative recombination mechanism decreases with inc...

The characteristics of acoustic wave transmitting in a metamaterial-type seawater piping system are studied. The metamaterial pipe, which consists of a uniform pipe with air-water chamber Helmholtz resonators (HRs) mounted periodically along its axial direction, could generate a wide band gap in the low-frequency range, rendering the propagation of low-frequency acoustic waves in the piping sys...