Abstract:
Plasma generating apparatus including a high vacuum processing chamber, a transformer type plasmatron, coupled with the high vacuum processing chamber, and at least one gas source, coupled with the transformer type plasmatron, for introducing at least one gas into the transformer type plasmatron, the high vacuum processing chamber comprising at least one entry port, the transformer type plasmatron including a radio frequency power source, for generating alternating current power, a plurality of conductors, coupled with the radio frequency power source, a closed loop discharge chamber, for confining the gas, a plurality of high permeability magnetic cores, coupled around an outer portion of the closed loop discharge chamber and with the conductors, a plurality of apertures, located along an inner portion of the closed loop discharge chamber, and at least two dielectric gaskets, for coupling the inner portion with the outer portion, wherein the entry port is configured to receive the inner portion such that the inner portion physically penetrates the high vacuum processing chamber, the conductors forming a primary winding around the plurality of high permeability magnetic cores, the gas in the closed loop discharge chamber forming a secondary winding around the plurality of high permeability magnetic cores, wherein the transformer type plasmatron igniting the gas into at least one respective plasma when the conductors are provided with the alternating current power, and the apertures releasing the respective plasma from the inner portion into the high vacuum processing chamber.
Abstract:
Method for crystal growth from a surfactant of a metal-nonmetal (MN) compound, including the procedures of providing a seed crystal, introducing atoms of a first metal to contact with the seed crystal thus forming a thin liquid metal wetting layer on a surface of the seed crystal, setting a temperature of the seed crystal below a minimal temperature required for dissolving MN molecules in the wetting layer and above a melting point of the first metal, each one of the MN molecules being formed from an atom of a second metal and an atom of a first nonmetal, introducing the MN molecules which form an MN surfactant monolayer, thereby facilitating a formation of the wetting layer between the MN surfactant monolayer and the surface of the seed crystal, and regulating a thickness of the wetting layer, thereby growing an epitaxial layer of the MN compound on the seed crystal.
Abstract:
A method for forming a gallium nitride crystal sheet. According to the method a metal melt, including gallium, is brought to a vacuum of 0.01 Pa or lower and is heated to a growth temperature of between approximately 860 o C and approximately 870 o C. A nitrogen plasma is applied to the surface of the melt at a sub-atmospheric working pressure, until a gallium nitride crystal sheet is formed on top. Preferably, the growth temperature is of 863 o C, and the working pressure is within the range of 0.05 Pa and 2.5 Pa. According to a preferred embodiment, application of the plasma includes introducing nitrogen gas to the metal melt at the working pressure, igniting the gas into plasma, directing the plasma to the surface of the metal melt, until gallium nitride crystals crystallize thereon, and maintaining the working pressure and the directed plasma until a gallium nitride crystal sheet is formed.
Abstract:
Plasma generating apparatus including a high vacuum processing chamber, a transformer type plasmatron, coupled with the high vacuum processing chamber, and at least one gas source, coupled with the transformer type plasmatron, for introducing at least one gas into the transformer type plasmatron, the high vacuum processing chamber comprising at least one entry port, the transformer type plasmatron including a radio frequency power source, for generating alternating current power, a plurality of conductors, coupled with the radio frequency power source, a closed loop discharge chamber, for confining the gas, a plurality of high permeability magnetic cores, coupled around an outer portion of the closed loop discharge chamber and with the conductors, a plurality of apertures, located along an inner portion of the closed loop discharge chamber, and at least two dielectric gaskets, for coupling the inner portion with the outer portion, wherein the entry port is configured to receive the inner portion such that the inner portion physically penetrates the high vacuum processing chamber, the conductors forming a primary winding around the plurality of high permeability magnetic cores, the gas in the closed loop discharge chamber forming a secondary winding around the plurality of high permeability magnetic cores, wherein the transformer type plasmatron igniting the gas into at least one respective plasma when the conductors are provided with the alternating current power, and the apertures releasing the respective plasma from the inner portion into the high vacuum processing chamber.
Abstract:
Solar system for converting solar radiation into electric energy, the system comprising: a refraction array and a converting array, the refracting array including at least one refraction sub array, each of the refraction sub arrays including a plurality of refraction sites, each of the refraction sites refracting variable approach angle collimated solar radiation into a plurality of solar rays, each of the solar rays being of a different waveband, each of the refraction sites directing each of the solar rays, refracted thereby, in a different direction, the different direction being at least dependent on the approach angle of the solar radiation, the converting array including a plurality of broadband converting cells, positioned such that light refracted by the refraction array impinges on the converting array, wherein at any given moment, each of the converting cells receives solar rays of a specific waveband originating from different refraction sites and arriving from different directions thereto.
Abstract:
Solar system for converting solar radiation into electric energy, the system comprising: a refraction array and a converting array, the refracting array including at least one refraction sub array, each of the refraction sub arrays including a plurality of refraction sites, each of the refraction sites refracting variable approach angle collimated solar radiation into a plurality of solar rays, each of the solar rays being of a different waveband, each of the refraction sites directing each of the solar rays, refracted thereby, in a different direction, the different direction being at least dependent on the approach angle of the solar radiation, the converting array including a plurality of broadband converting cells, positioned such that light refracted by the refraction array impinges on the converting array, wherein at any given moment, each of the converting cells receives solar rays of a specific waveband originating from different refraction sites and arriving from different directions thereto.
Abstract:
Reactive evaporation method for forming a group III-V amorphous material attached to a substrate, the method including the procedures of subjecting the substrate to an ambient pressure of no greater than 0.01 Pa, and introducing active group-V matter to the surface of the substrate at a working pressure of between 0.05 Pa and 2.5 Pa, and group III metal vapor, until an amorphous group III-V material layer is formed on the surface.
Abstract:
Reactive evaporation method for forming a group III-V amorphous material attached to a substrate, the method including the procedures of subjecting the substrate to an ambient pressure of no greater than 0.01 Pa, and introducing active group-V matter to the surface of the substrate at a working pressure of between 0.05 Pa and 2.5 Pa, and group III metal vapor, until an amorphous group III-V material layer is formed on the surface.
Abstract:
A method for forming a gallium nitride crystal sheet. According to the method a metal melt, including gallium, is brought to a vacuum of 0.01 Pa or lower and is heated to a growth temperature of between approximately 860oC and approximately 870oC. A nitrogen plasma is applied to the surface of the melt at a sub-atmospheric working pressure, until a gallium nitride crystal sheet is formed on top. Preferably, the growth temperature is of 863oC, and the working pressure is within the range of 0.05 Pa and 2.5 Pa. According to a preferred embodiment, application of the plasma includes introducing nitrogen gas to the metal melt at the working pressure, igniting the gas into plasma, directing the plasma to the surface of the metal melt, until gallium nitride crystals crystallize thereon, and maintaining the working pressure and the directed plasma until a gallium nitride crystal sheet is formed.
Abstract:
A method for forming a uniformly oriented crystalline sheet, wherein a plurality of crystallites are introduced into a liquid. At least a portion of the crystallites float on the surface of the liquid, and are induced to self orientate until they are uniformly oriented in a compact mosaic configuration, while their sintering is prevented. A uniformly oriented crystalline sheet is formed from the compact mosaic configuration, for example, by sintering the crystallites. An apparatus for forming a crystalline sheet includes a container containing a liquid, wherein a plurality of crystallites are introduced and at least a portion thereof float on the surface of the liquid without sintering. The apparatus also includes a flow unit for inducing a flow of the liquid which moves the floating crystallites, and self-orientation means for allowing self-orientation of the floating crystallites, without sintering, until the floating crystallites are uniformly oriented in a compact mosaic configuration, ready for forming a uniformly oriented crystalline sheet, for example, by sintering the crystallites.