Abstract:
The invention relates to a method for the production of monocrystalline crystals comprising: a step for assembly of a first substrate (2) and at least one film (4) or at least one layer of a second monocrystalline material (6) and a step for the growth of said first material on the film or the thin layer.
Abstract:
The invention relates to a method for producing layered structures, whereby a preferably porous material layer with hollow cavities is produced on or from a monocrystalline p-type or n-type Si substrate. The layered structure or a part thereof is applied to said layer and subsequently, the layered structure or a part thereof is separated from the substrate using said layer as a desired break-off point, e.g. by producing mechanical tension inside said layer or on a boundary surface of said layer. The method is characterized in that the surface of the substrate is structured before the porous layer is produced or that the surface of the porous layer is structured.
Abstract:
A method of growing a substantially dislocation-free hollowed core silicon crystal is disclosed, the method including providing a substantially circular silicon seed, the seed including a top surface, a bottom surface, an outer surface and a notch within the outer surface; securing the seed into a chuck by inserting a retainer piece into the notch on the outer surface of the silicon seed; lowering the silicon seed into molten silicon within a crucible; gradually withdrawing the silicon seed from the molten silicon to form a substantially dislocation-free hollowed core silicon crystal. Silicon crystal seeds are also disclosed, as are systems and apparatus for forming hollow silicon crystals.
Abstract:
Carbon nanotubes are formed on a surface of a substrate using a plasma chemical deposition process. After the nanotubes have been grown, a post-treatment step is performed on the newly formed nanotube structures. The post-treatment removes graphite and other carbon particles from the walls of the grown nanotubes and controls the thickness of the nanotube layer. The post-treatment is performed with the plasma at the same substrate temperature. For the post-treatment, the hydrogen containing gas is used as a plasma source gas. During the transition from the nanotube growth stop to the post treatment step, the pressure in the plasma process chamber is stabilized with the aforementioned purifying gas without shutting off the plasma in the chamber. This eliminates the need to purge and evacuate the plasma process chamber.
Abstract:
The present invention provides a process of controllable growth of pure carbon structures including planar films, of single-walled fullerenes (SWF), multi-walled fullerenes (MWF), well oriented single-walled nanotubes (SWNT) and multi-walled nanotubes (MWNT) on various substrates. Structures can be built up on the surface which include any combination of fullerenes, nanotubes, bent or inclined nanotubes with single or multiple bends in the nanotubes.
Abstract:
The invention relates to metallic articles for industrial use, more specifically to a method for producing a thin metallic monocrystalline wire having a diameter ranging from 0.01 to 5.0 mkm. The inventive method consists in carrying out the plastic deformation of a wire having a deformation rate of higher than 98 % by twisting two wires in spiral through time at a pitch angle ranging from 20 to 58° with respect to the longitudinal axis thereof and at a predetermined twisting speed through time during the thermal processing and the cleaning of the thus produced wire from polycrystalline metal residuals. Said method is also characterised in that the shear plastic deformation of the wire at a deformation rate of higher than 98 % is carried out by twisting one wire about the longitudinal axis thereof when the metal is in a yielded state in such a way that filamentary monocrystals are formed. In individual cases, the deformation of metallic wire is carried out at a temperature ranging from (-200°C) to 400 °C. All processing parameters are experimentally defined. The monocrystallinity of the wire is confirmed by X-ray analysis. In cases when the monocrystalline wire with polycrystalline residuals can not be used, the cleaning of a monocrystalline filament is carried out with the aid of a chemical method.
Abstract:
The invention relates to a method for producing layered structures, whereby a preferably porous material layer with hollow cavities is produced on or from a monocrystalline p-type or n-type Si substrate. The layered structure or a part thereof is applied to said layer and subsequently, the layered structure or a part thereof is separated from the substrate using said layer as a desired break-off point, e.g. by producing mechanical tension inside said layer or on a boundary surface of said layer. The method is characterized in that the surface of the substrate is structured before the porous layer is produced or that the surface of the porous layer is structured.