GaN was grown on porous silicon (PS) substrates by Metalorganic Vapour Phase Epitaxy at temperature of 1050 8C. An additional AlN buffer layer is used between GaN and PS. The crystalline quality and surface morphology of GaN films were studied by X-ray diffraction and scanning electron microscope (SEM), respectively. Preferential growth of hexagonal GaN with h00.1i direction is observed and is ...

Transmission Electron Microscopy and x-ray diffraction were used to study compositional modulation in InxGa1-x N layers grown with compositions close to the miscibility gap. The samples (0.34 < x < 0.8) were deposited by molecular beam epitaxy using either a 200-nm-thick AlN or GaN buffer layer grown on a sapphire substrate. In the TEM imaging mode this modulation is seen as black/white fringes...

The performance of hot-forging dies, in which the die cavity is weld-deposited with a layer of modified H12 hot-work tool steel, has been studied, using a continuous monitoring of the die condition as well as macroscopic and microscopic examination. It was observed that the thickness of the hard upper ‘capping layer’ and that of an intermediate ‘buffer layer’ have a pronounced effect on the lif...

Buffer layers that control electrochemical reactions and physical interactions at electrode/film interfaces are key components of an organic photovoltaic cell. Here the structure and properties of layers of semi-rigid poly(3-hexylthiophene) (P3HT) chains tethered at a surface are investigated, and these functional systems are applied in an organic photovoltaic device. Areal density of P3HT chai...