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Physical Vapor Transport (physical + vapor_transport)
Selected AbstractsElastic constants of aluminum nitridePHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 1 2007M. Kazan Abstract We report on the application of Brillouin spectroscopy as an approach to non-destructive optical characterization of the elastic constants of semiconductors with the wurtzite symmetry. Three different configurations were used to achieve a complete determination of the elastic stiffness constants of bulk AlN substrates grown by the Physical Vapor Transport (PVT) method. The scattering diagrams of these three configurations are presented showing the geometrical arrangements necessary to observe all the elastic stiffness constants for the partially nontransparent wurtzite type of the crystal structure. Because aluminum nitride (AlN) is a suitable material for the fabrication of light emitting devices, the characterization of its elastic constants was carried out very precisely to provide a reliable data which can be used for the determination of residual stress arising during the growth of AlN thin films or wide band gap semiconductor thin films on substrates of AlN. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Effect of AlN doping on the growth morphology of SiCCRYSTAL RESEARCH AND TECHNOLOGY, Issue 9 2009N. B. Singh Abstract AlN doped SiC films were deposited on on-axis Si-face 4H-SiC (0001) substrates by the physical vapor transport (PVT) method. Thick film in the range of 20 ,m range was grown and morphology was characterized. Films were grown by physical vapor deposition (PVD) in a vertical geometry in the nitrogen atmosphere. We observed that nucleation occurred in the form of discs and growth occurred in hexagonal geometry. The X-ray studies showed (001) orientation and full width of half maxima (FWHM) was less than 0.1° indicating good crystallinity. We also observed that film deposited on the carbon crucible had long needles with anisotropic growth very similar to that of pure AlN. Some of the needles grew up to sizes of 200 ,m in length and 40 to 50 ,m in width. It is clear that annealing of SiC-AlN powder or high temperature physical vapor deposition produces similar crystal structure for producing AlN-SiC solid solution. SEM studies indicated that facetted hexagons grew on the top of each other and coarsened and merged to form cm size grains on the substrate. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Micrometer-Sized Organic Single Crystals, Anisotropic Transport, and Field-Effect Transistors of a Fused-Ring ThienoaceneADVANCED MATERIALS, Issue 44 2009Rongjin Li Hexagonal micrometer-sized organic single crystals of a fused-ring thienoacene are grown controllably by physical vapor transport over a large area. A "two-dimensional organic-ribbon mask" technique is developed to fabricate organic field-effect transistors based on an individual microcrystal. The accomplished transistors exhibit mobility as high as 1.8,cm2V,1s,1 with on/off ratios of typically >107. [source] High-Performance Organic Single-Crystal Transistors and Digital Inverters of an Anthracene DerivativeADVANCED MATERIALS, Issue 36 2009Lang Jiang Single-crystal disks of di(phenylvinyl) anthracene, micro- or nanometer-sized and flexible, are produced by physical vapor transport. Subsequently, single- crystal transistors are fabricated by the organic ribbon mask method and integrated to produce high-performance inverters. The mobility of the transistors, the mobility anisotropy along different crystal axes of the disks, and the maximum gain of the inverters are reported. [source] | ||||||||||