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GaN Nanowires (gan + nanowire)
Selected AbstractsDC characteristics and high frequency response of GaN nanowire metal-oxide-semiconductor field-effect transistorPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue S2 2009Jeng-Wei Yu Abstract We report selected site lateral growth of crystalline [110] GaN nanowire (NW) with high channel mobility of 1050 cm2/V-s on SiO2/p-Si. This scheme enables photolithographic fabrication of top-gated GaN NW-MOSFET of 60 nm dia. and 2 ,m gate length. Device parameters with gm of 25 ,S, saturation current of 90 ,A, and cut-off frequency fT at 14 GHz have been extracted. In an active load configuration of GaN NW-MOSFET inverter we reported voltage gain of 2 and a high current on/off ratio of 104. These observations suggest promising functional diversification of the GaN NW-MOSFET on the Si-based CMOS platform for the sub-50 nm technology nodes. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Morphology control of GaN nanowires by vapor-liquid-solid growthPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 9 2008Y. Inoue Abstract We synthesized GaN nanowires on sapphire substrate by metal organic chemical vapour deposition. The GaN nanowires were grown via vapor-liquid-solid (VLS) growth catalyzed with Ni thin film. Shape of nanowires depended on the substrate temperature and the growth pressure. The wire-like structure with high aspect ratio changed into the tapered structure with increasing substrate temperature, and with increasing the growth pressure. This dependency was attributed to the change of the surface diffusion length of source atoms. The VLS growth of GaN nanowire was revealed that the source species, absorbed at the eutectic droplet, came along the side wall of the nanowire as well as other semiconductor nanowires. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Controlled Nucleation of GaN Nanowires Grown with Molecular Beam EpitaxyADVANCED FUNCTIONAL MATERIALS, Issue 17 2010Kris A. Bertness Abstract The location of GaN nanowires is controlled with essentially perfect selectivity using patterned SiNx prior to molecular beam epitaxy growth. Nanowire growth is uniform within mask openings and absent on the mask surface for over 95% of the usable area of a 76 mm diameter substrate. The diameters of the resulting nanowires are controlled by the size of the mask openings. Openings of approximately 500 nm or less produce single nanowires with symmetrically faceted tips. [source] Nanowire-Templated Epitaxial Growth: Nanowire-Templated Lateral Epitaxial Growth of Low-Dislocation Density Nonpolar a -Plane GaN on r -Plane Sapphire (Adv. Mater.ADVANCED MATERIALS, Issue 23 200923/2009) George Wang and co-workers report on p. 2416 that low dislocation density a -plane GaN films can be grown by the coalescence of vertically-aligned, single-crystalline GaN nanowires on lattice-mismatched r -plane sapphire. In this technique, shown by the artists' rendering on the inside cover, the nanowires facilitate dramatic strain relaxation in the suspended GaN film, leading to a large reduction in defects. [source] Cover Picture: Direction-Dependent Homoepitaxial Growth of GaN Nanowires (Adv. Mater.ADVANCED MATERIALS, Issue 2 20062/2006) Abstract GaN nanowires with vastly different morphologies depending upon their growth direction can be produced by direct nitridation and vapor transport of Ga in disassociated ammonia, report Sunkara and co-workers on p.,216. Nanowires grown along the c -direction develop hexagonal-prism island morphologies, while wires grown along the a -direction form uniform, belt-shaped morphologies. A "ballistic" phenomenon involving the 1D transport of adatoms on the non-polar surfaces of <0001> GaN nanowires is proposed to explain the prismatic island morphologies. [source] Direction-Dependent Homoepitaxial Growth of GaN Nanowires,ADVANCED MATERIALS, Issue 2 2006H. Li GaN nanowires with vastly different morphologies depending upon the growth direction are produced by direct nitridation and vapor transport of Ga in disassociated ammonia. Nanowires grown homoepitaxially along the c -direction develop hexagonal-prism island morphologies (see Figure, left, and Cover), while wires grown along the a -direction form uniform, belt-shaped morphologies (Figure, right). A "ballistic" transport phenomenon for adatoms is proposed to explain the observed prismatic island morphologies. [source] Epitaxial growth of aligned GaN nanowires and nanobridgesPHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 6 2007Kyungkon Kim Abstract Homo-epitaxialy grown aligned GaN nanowires were prepared on crystalline GaN mesas. The GaN nanowires showed preferential growth along the ,100, direction (m -axis direction). By using selectively positioned and crystallographically well defined GaN epitaxial lateral overgrowth (ELO) mesas as substrate, we obtained horizontally aligned GaN nanowires, in comb-like arrays and hexagonal network interconnecting the ELO mesas. Preliminary testing of the nanomechanical behavior of horizontal nanowires is reported. Combination of ELO with nanowire synthesis is expected to provide a new paradigm for nano-electronic and electromechanical devices. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Morphology control of GaN nanowires by vapor-liquid-solid growthPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 9 2008Y. Inoue Abstract We synthesized GaN nanowires on sapphire substrate by metal organic chemical vapour deposition. The GaN nanowires were grown via vapor-liquid-solid (VLS) growth catalyzed with Ni thin film. Shape of nanowires depended on the substrate temperature and the growth pressure. The wire-like structure with high aspect ratio changed into the tapered structure with increasing substrate temperature, and with increasing the growth pressure. This dependency was attributed to the change of the surface diffusion length of source atoms. The VLS growth of GaN nanowire was revealed that the source species, absorbed at the eutectic droplet, came along the side wall of the nanowire as well as other semiconductor nanowires. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Influence of Mg Doping on GaN NanowiresCHEMPHYSCHEM, Issue 3 2009Dongdong Zhang Abstract Magnesium-doped GaN nanowires with different dopant concentrations are synthesized and their morphology, structure, growth properties, crystallinity, and optical properties investigated. The nanowires are single-crystalline with hexagonal wurzite structure, and doping with 5 atom,% of Mg gives nanowires with the best morphology and crystallinity (see HRTEM image). Magnesium-doped GaN nanowires with different dopant concentrations are synthesized by ammoniating Ga2O3 thin films doped with Mg at 900,°C. Scanning electron microscopy (SEM), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX), high-resolution transmission electron microscopy (HRTEM), and room-temperature photoluminescence (PL) are employed to characterize the influences on the morphology, structure, crystallinity, and optical properties of Mg-doped GaN nanowires. The results demonstrate that the nanowires are single-crystalline with hexagonal wurzite structure. GaN nanowires doped with 5 atom,% of Mg have the best morphology and crystallinity with a single-crystalline structure, and at this composition the PL spectrum with the strongest UV peak is observed. The growth mechanism of crystalline GaN nanowires is discussed briefly. [source] | |||||||||||||