Abstract: One-dimensional nanostructures having uniform diameters of less than approximately 200 nm. These inventive nanostructures, which we refer to as “nanowires”, include single-crystalline homostructures as well as heterostructures of at least two single-crystalline materials having different chemical compositions. Because single-crystalline materials are used to form the heterostructure, the resultant heterostructure will be single-crystalline as well. The nanowire heterostructures are generally based on a semiconducting wire wherein the doping and composition are controlled in either the longitudinal or radial directions, or in both directions, to yield a wire that comprises different materials. Examples of resulting nanowire heterostructures include a longitudinal heterostructure nanowire (LOHN) and a coaxial heterostructure nanowire (COHN).

Abstract: A method of separating a thin film of GaN epitaxially grown on a sapphire substrate. The thin film is bonded to an acceptor substrate, and the sapphire substrate is laser irradiated with a scanned beam at a wavelength at which sapphire is transparent but the GaN is strongly absorbing, e.g., 248 nm. After the laser irradiation, the sample is heated above the melting point of gallium, i.e., above 30° C., and the acceptor substrate and attached GaN thin film are removed from the sapphire growth substrate. If the acceptor substrate is flexible, the GaN thin film can be scribed along cleavage planes of the GaN, and, when the flexible substrate is bent, the GaN film cleaves on those planes. Thereby, GaN lasers and other electronic and opto-electronic devices can be formed.

Abstract: A method of separating a thin film of GaN epitaxially grown on a sapphire substrate. The thin film is bonded to an acceptor substrate, and the sapphire substrate is laser irradiated with a scanned beam at a wavelength at which sapphire is transparent but the GaN is strongly absorbing, e.g., 248 nm. After the laser irradiation, the sample is heated above the melting point of gallium, i.e., above 30.degree. C., and the acceptor substrate and attached GaN thin film are removed from the sapphire growth substrate. If the acceptor substrate is flexible, the GaN thin film can be scribed along cleavage planes of the GaN, and, when the flexible substrate is bent, the GaN film cleaves on those planes. Thereby, GaN lasers and other electronic and opto-electronic devices can be formed.

Abstract: A method of bonding together two dissimilar planar bodies, one of which is a semiconductor. A film of palladium is deposited on one of the bodies. The two bodies are pressed together with moderate force with the palladium in between. The palladium chemically reacts with the semiconductor and, at least in the case of GaAs, dissolves the surface oxide and forms a crystalline palladium/semiconductor product topotaxial with the semiconductor.

Abstract: A non-volatile memory element based upon a thin epitaxial film of manganese aluminum upon a III-V semiconductor is described. The film is stable at elevated temperatures required for III-V semiconductor device processing, so permitting the monolithic integration of non-volatile memory elements with III-V semiconductor electronic and photonic devices.

Abstract: A flexible superconducting wire element comprising a flexible tape of partially stabilized (.about.3 mole % yttria) yttria-stabilized zirconia (YSZ), a buffer layer of fully stabilized (between 8 and 18 mole % yttria, preferably 9 mole %) YSZ deposited on the flexible tape, and a high-temperature, perovskite superconductor such as YBaCuO deposited on the buffer layer. The tape provides the strength while remaining flexible. The buffer layer is flexible because of its thinness (.about.100 nm), but provides a good crystallographic template for the growth of oriented perovskite superconductors. Thereby, the superconducting properties of the wire element approach those of a superconducting film deposited on a rigid substrate.

Abstract: A class of intermetallic compound contact materials for III-V semiconductors is obtained by depositing successively and concurrently a thin film of a transition metal and a Group III metal upon the semiconductor and annealing the resultant structure, so resulting in the formation of a monocrystalline intermetallic contact. The contacts are stable at temperatures ranging from 600.degree.-900.degree. C. and may be fabricated by conventional vacuum deposition.

Abstract: A class of intermetallic compound contact materials for III-V semiconductors is obtained by depositing successively and concurrently a thin film of a transition metal and a Group III metal upon the semiconductor and annealing the resultant structure, so resulting in the formation of a monocrystalline intermetallic contact. The contacts are stable at temperatures ranging from 600-900.degree. C. and may be fabricated by conventional vacuum deposition.

Abstract: An ohmic contact to a semiconductor such as GaAs and its method of making in which a thin layer of Pd is overlaid preferably with a layer of Group-IV element such as Ge followed by another layer of Pd. This structure is then overlaid with a layer of Pd and In. The atomic ratio of the Pd and In in the entire structure lies between 0.9 and 1.5. This structure is then annealed at a temperature between 350.degree. C. and 675.degree. C. There results a very thin crystalline layer of Ge-doped InGaAs adjacent the GaAs and an overlying PdIn alloy layer providing a contact resistance in the range of 0.1-1 .OMEGA.-mm.

Abstract: A class of intermetallic compound contact materials for III-V semiconductors is obtained by depositing successively and concurrently a thin film of a transition metal and a Group III metal upon the semiconductor and annealing the resultant structure, so resulting in the formation of a monocrystalline intermetallic contact. The contacts are stable at temperatures ranging from 600.degree.-900.degree. C. and may be fabricated by conventional vacuum deposition.

Abstract: Disclosed is a heliostat collector apparatus comprising at least one heliostat suspended from a plurality of longitudinally extending linkage means. An enclosure structure is disposed adjacent the heliostat and provides a means for allowing the heliostat to be substantially protected from weathering. A first drive means is operatively connected to the heliostat to effect steering thereof in at least one of first and second predetermined directions. Finally, a frame member is adapted for supporting the heliostat at an inner portion thereof. The frame includes a plurality of outer expandable portions. Each one of the expandable portions is adapted to slidably engage a corresponding one of the plurality of linkage means. The expandable portions are further adapted to allow the heliostat to be slidably moved along the linkage means in directions away from and towards the enclosure structure and to substantially reduce stress acting on the heliostat during steering.