The effect of Fe-Ga pair defects on minority-carrier lifetime τ in high-purity, dislocation-free float-zoned Si is presented, and their properties are documented by deeplevel transient spectroscopy and annealing studies. The typical τ of Fe-Ga co-doped crystals (0.4 μs) was dramatically lower than τ of crystals doped with similar amounts of either Fe alone (12 μs) or Ga alone (1,400 μs), contra...

We demonstrate a mid-infrared Raman-soliton continuum extending from 1.9 to 3 µm in a highly germanium-doped silica-clad fiber, pumped by a nanotube mode-locked thulium-doped fiber system, delivering 12 kW sub-picosecond pulses at 1.95 µm. This simple and robust source of light covers a portion of the atmospheric transmission window.

We report the synthesis of a Fe-porphyrin-like carbon nanotube from conventional plasma-enhanced chemical vapor deposition. Covalent but seamless incorporation of the 5-6-5-6 porphyrinic Fe-N(4) moiety into the graphene hexagonal side wall was elucidated by x-ray and ultraviolet photoemission spectroscopies and first-principles electronic structure calculations. The resulting biomimetic nanotub...

Nb-doped TiO(2) nanotube (with C(Nb) < 1 wt%) layers were successfully fabricated by self-ordered electrochemical anodization of Ti-Nb alloys. When used in dye-sensitized solar cells the efficiency enhanced by up to 30% compared to non-doped TiO(2) nanotubes. IMVS measurements indicate the beneficial effect to be due to lower recombination losses.

We have studied the mechanism of the initial stages of nitrogen-doped single-walled carbon nanotube growth illustrated for the case of a floating catalyst chemical vapor deposition system, which uses carbon monoxide (CO) and ammonia (NH(3)) as precursors and iron as a catalyst. We performed first-principles electronic-structure calculations, fully incorporating the effects of spin polarization ...

In this work, the effects of As-doped on the adsorption of oxygen gas on the outer and inner surface ofboron nitride nanotube (BNNTs) is investigated. The structural parameters, quantum properties involving:bond length, bond angle, HOMO-LUMO orbital, gapenergy, electron affinity, electronegativity, chemicalpotential, global hardness, global softness and NMR parameters of BNNTs are calculated at...

Magnetic hysteresis and magnetic relaxation measurements have been performed to study vortex pinning behaviors for pure, Fe doped and heavily Pb doped Bi2212 single crystals. Unlike pure and Fe doped Bi2212 crystals, heavily Pb doped crystal showed strong vortex pinning behavior. We interpret the strong pinning in heavily Pb doped Bi2212 single crystals as arising from the improved Josephson co...

Fe-N-C catalysts with high O2 reduction performance are crucial for displacing Pt in low-temperature fuel cells. However, insufficient understanding of which reaction steps are catalyzed by what sites limits their progress. The nature of sites were investigated that are active toward H2 O2 reduction, a key intermediate during indirect O2 reduction and a source of deactivation in fuel cells. Cat...

In this paper, 2wt.% Fe doped TiO2 nanopowder was prepared by a combination of sol-gel and mechanical alloying methods. The mechanical alloying of Fe powder with Ti(OH)4 gel produced from the sol-gel method was used to produce Fe doped TiO2 nanopowder. The synthesized samples were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and diffuse reflectan...

Abstract: Electrical sensitivity of a beryllium oxide nanotube (BeONT) was examined toward (C5H5N) molecule by using density functional theory (DFT) calculations at the B3LYP/6-31(d) level, and it was found that the adsorption energy (Ead) of pyridine on the pristine nanotubes is   a bout -73.29kcal/mol. But when nanotubes has been doped with S and P atomes , t...