by means of first principles calculations we show that both rutile and anatase phases of bulk tio2 doped by s, se or pb can display substantial decreasing in the band gap (up to 50%), while doping by zr does not sizably affect the band-gap value. moreover, the absorption edge is shifted (up to 1 ev) to the lower energy range in the case of tio2 doped by s or pb that opens a way to enhancing of ...

li2ni8o10 and limn2o4 nanoparticles as cathode materials of lithium ion battery, were successfully synthesized using lithium acetate, nickel and manganese acetate as li, ni and mn sources and stearic acid as a complexing reagent. the structure of the obtained products were characterized by ft-ir and xrd. the shape, size and distribution of the li2ni8o10 and limn2o4 nanoparticles were observed b...

Zinc sulfide (ZnS) films were deposited through a simple and low cost spray pyrolytic technique using mixed aqueous solutions of zinc nitrate and thiourea. The structural and optical properties of these films were investigated as a function of initial (Zn:S) molar ratio in the precursor solution, which varied between (1:1) and (1:3). X-ray diffraction (XRD) analysis revealed that wurtzite...

The Photoexcited carrier lifetime (τ) and peak to valley transmission difference (ΔTp-v) in direct and indirect band gap crystals has been investigated by the use of single beam open and closed aperture z-scan technique using frequency doubled Nd:YAG laser. The peak to valley transmission difference (ΔTp-v) is found to be of the order of 10-2 in case of direct band gap crystals and of the order...

sol-gel derived sulfur modified and pure zno nanorod were prepared using zinc chloride and thiocarbamide as raw materials. prepared nanorods were characterized by means of x-ray diffraction (xrd), thermogravimetry- differential scanning calorimetry (tg–dsc), uv- vis absorption spectroscopy, brunauer emmett teller (bet) specific surface area and barrett joyner halenda (bjh) pore size distributio...

The influences of the filling rate on the photonic band gap properties of the two dimensional hex photonic crystals are investigated using the finite-difference time-domain method. When the filling rate f varies from 0.227 to 0.735 reminding the refractive index as 5, the number of the photonic band gaps decreases from 5 to 2 bands, the width of the photonic band gap between the transmit peaks ...

In this paper, a photonic crystal waveguide with point defects and lattice constant perturbations of +5%, -5% are being investigated. Firstly waveguide structures with constant and specific parameters are being studied and photonic band gap diagrams for TE/TM modes are depicted; then pulse propagation in the frequencies available in the band gap are shown. After that, effects of parameters like...