Electron mobility in the growth direction was measured using space charge limited current techniques in device-type nin structure nanocrystalline Si:H and nanocrystalline Ge:H structures. The films were grown on stainless steel foil using either hot wire or remote plasma enhanced chemical vapor deposition techniques. Grain size and crystallinity were measured using x ray and Raman spectroscopy. The size of grains in films was adjusted by changing the deposition conditions. It was found that large ⟨220⟩ grain sizes (∼56nm)" role="

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A compact planar channel four-port drop filter is developed experimentally and theoretically in the three-dimensional woodpile photonic crystal having a complete band gap. This consists of two waveguides separated by a defect in a single layer of the photonic crystal. Frequencies for channel dropping can be tuned throughout the band gap, by changing the size of the defect. Quality factors of approximately 1000 were measured. Simulations demonstrate directional energy transfer between the input and out put waveguides, through excitation of fields in the defect region. The planar nature of the filter is much more amenable to fabrication at optical length wavelengths.

We report on the growth of nanocrystalline Si:H films using both plasma CVD and remote hot wire deposition under systematically varied growth conditions. The films were grown from mixtures of silane and hydrogen. It was found that when the films were grown under low pressure VHF plasma growth conditions , the orientation of the film changed as the pressure increased. At the lowest pressures, the films were mainly <111> oriented, but changed to <220> orientation as the pressure increased. The grain size increased as the growth temperature increased. When the films were grown using remote hot wire deposition, the orientation depended upon both hydrogen dilution and growth temperature. As the hydrogen dilution increased, the <220> grain size became smaller. Grain size as large as 36 nm was obtained by controlling the growth conditions in hot wire deposition. As the growth temperature increased, the size of <220> grains increased. Growth rates also increased with increasing temperature. The data can be explained by invoking a growth model which recognizes that the natural growth direction for Si is <220>, since the surface energy is highest for (220) plane. Random nucleation leads to <111> grains. Bonded H is believed to inhibit the growth of <220> grains.

The resonant frequencies of a single cavity embedded in the three-dimensional layer-by-layer photonic crystal are studied with microwave experiments and transfer-scattering matrix method simulations. The effects of the number of cladding layers and the size of the embedded cavity on resonant frequencies and Q values are carefully examined. The fine increments of cavity size indicate a new pattern of relation between resonant frequencies and cavity sizes.