Annealing behavior and its glass composition dependence of photo-induced ESR in melt-quenched Ge-S glasses

Annealing behaviors of photo-induced ESR and optically-induced absorption edge shift have been studied in melt-quenched Ge-S glasses with various compositions. Annealing characteristic of photo-induced ESR has been found to be quite parallel to that of optically-induced edge shift. Composition dependence of them is correlated with that of the glass transition temperature.     

Plasma Enhanced Chemical Vapor Deposition of Fluorinated Amorphous Carbon Thin Films from Tetrafluoroethylene and Tetraisocyanatesilane

Fluorinated amorphous carbon films were prepared from tetrafluoroethylene (TFE; C₂F₄) and tetraisocyanatesilane (TICS; Si(NCO)₄) using an RF plasma enhanced chemical vapor deposition method for the purpose of application to inter layer low permittivity films used in large scale integrated circuits. Structure of the deposited films was investigated by X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. Adhesion characteristics were examined by a tape-peel method. Permittivity of the films was investigated from capacitance measurement on metal-insulator-semiconductor structure. The structural analysis revealed that the deposited films contained imide-like group in spite of the fact that TICS molecules contained isocyanate group . The films deposited under the flow ratio TICS/(TFE + TICS) = 70% showed permittivity of 2.3, good adhesion on silicon substrates, and higher thermal stability than the films deposited without TICS.     

Three-Dimensionally Integrated Micro-solution Plasma: Numerical Feasibility Study and Practical Applications

This paper describes effects of design parameters for a three-dimensionally integrated micro-solution plasma (3D IMSP) reactor, which generates a large amount of microplasma in gas bubbles flowing with a liquid medium through a porous dielectric material. Electric fields in gas bubbles are calculated by solving Maxwell’s equations under the electro-quasi-static approximation. The calculated electric fields in the bubbles can be high enough for igniting electrical discharge in the bubbles even if the bubbles are surrounded by electrically conductive liquid. We show importance of higher permittivity of a dielectric-reactor tube and a higher voltage-rise rate for obtaining higher electric fields in the bubbles. Using a proto type 3D IMSP reactor, we demonstrate synthesis of gold nanoparticles and decomposition of methylene blue molecules in aqueous solution.     

Microcrystalline formation in sputtered a-Si: H films

Microcrystalline formation in hydrogenated silicon films deposited under high hydrogen partial pressures by reactive r.f. sputtering method has been studied by means of small angle scattering of X-ray. The existence of microcrystalline regions are detected in samples deposited under high hydrogen partial pressure above 40% at the total gas pressure of H₂ and Ar mixture of 2 × 10^-2 torr. The mean radius of microcrystalline regions increases with increasing hydrogen partial pressure. Relation between the presence of microcrystalline state and the electric properties of films is briefly discussed.     

Frequency dependence of dark conductivity in glow-discharged a-Si:H

Frequency dependence of the dark conductivity at room temperature has been measured on glow-discharged amorphous hydrogenated silicon films deposited at various substrate temperatures. In high substrate temperature samples, a frequency-independent conductivity region appears at low frequencies. It is discussed that the observed results are possible to be understood in terms of the paramicrocrystalline formation in the films deposited at high substrate temperatures.     

Cleavage of cyclopropene ring by means of transition metal salts

The oxidative ring cleavage of 1,3,3-trimethylcyclopropene (1) with Hg(OAc)₂ in methylene chloride gives 1,1-diacetoxy-2,3-dimethyl-2-butene (5). The reaction of 1 with TI(OAc)₃ or Pb(OAc)₄ gives in addition to 5, 3,3-diacetoxy-2-methylpropene and 2-acetoxy-4-methyl-1,3-pentadiene. These products are explained by assuming the addition of metal acetates onto the double bond of 1 followed by the ring cleavage to give vinylcarbene-metal acetate complexes or inverse ylides. The reaction of benzocyclopropene (14) with Hg(OAc)₂ affords bis(o-acetoxymethylphenyl)mercury as a single product. Cyclopropene ring cleavage of 14 effected by Cu(II) or Ag(l) acetate furnishes 9,10-dihydrophenanthrene and benzyl acetate. These products are ascribed to the intermediary vinylcarbene- metal acetate complexes produced from 14.     

Optical waveguiding in epitaxial InxGa1−xAs single layer

In_xGa_1?xAs planar waveguide with propagation loss as low as 0.4 cm^-1 was obtained at 1.06 μm. The possible propagation loss in the In_xGa_1?xAs waveguide was investigated.     

Magneto-Luminescence of excitons bound to neutral acceptor in cadmium telluride

The radiative recombination of excitons bound to neutral acceptor (A⁰, X) in high-purity CdTe has been investigated in magnetic fields up to 100 KG. A doublet structure observed in (A⁰, X) emission line is explained by considering the j-j coupling between two holes and an electron. Zeeman splittings in emission lines originate from the transition between J = 1/2 and 3/2 states in bound-exciton complex, and the acceptor-ground state. It is supposed that the acceptor which binds excitons is due to certain complex having C_3υ symmetry which is lower than the host lattice.