In this paper, for developing analytical and semi-analytical methods to evaluate band structure in photonic quasicrystals the perturbation theory is examined. It is shown that more isotropic and complete photonic band gap can be observed under low dielectric contrast for photonic quasicrystals in comparison with ordinary crystals and because of this feature of photonic quasicrystals, perturbati...

The ability to fine-tune band gap and band inversion in topological materials is highly desirable for the development of novel functional devices. Here we propose that the electronic properties of a free-standing nanomembrane of topological crystalline insulator (TCI) SnTe and Pb1−xSnx(Se,Te) are highly tunable by engineering elastic strain and controlling membrane thickness, resulting in tunab...

s-doped and bare mesoporous tio2 were prepared using titanium tetraisopropoxide and thiocarbamide as raw materials. prepared materials were characterized by means of fourier transform infrared spectroscopy ft-ir, thermogravimetry-differential scanning calorimetry (tg-dsc), x-ray diffraction (xrd), uv–vis absorption spectroscopy, brunauer–emmett–teller (bet) specific surface area and barrett–joy...

zno nanostructures have been synthesized by a simple reflux method, using different ionic liquids, such as 1-benzyl-3-methylimidazolium bromide ([bzmim][br]), 1,1'-(1,4 phenylenebis (methylene)) bis (3-methyl-1h-imidazol-3-ium) bromide ([mm-1,4-dbzim2][br]2) and 1-phenacyl-3-methylimidazolium bromide ([pmim][br]), with different amount of sodium hydroxide in water. also the effect of reaction t...