Hi-z Technology, Inc.

Hi-z Corporation

Other

Saeid Ghamaty

Norbert B Elsner

John Claude Bass

Velimir Jovanovic

Anthony Donaldson

A quantum well thermoelectric module providing very high conversion of heat energy in to electrical energy. In prefered embodiments the module provides electric power for monitoring, measuring or detecting any of a variety of things (such as temperature, smoke, other pollution, flow, fluid level and vibration) and a transmitter for transmitting information measured or detected. In a preferred embodiment wireless monitor systems are utilized to monitor conditions at various locations aboard a ship and to wirelessly transmit information about those conditions to a central location. Preferably, a finned unit is provided to efficiently transfer heat from a module surface to the environment. A preferred quantum well choice is p type BC/BC and n-type Si/SiGe legs. Another preferred choice is n-doped Si/SiGe for the n-legs and p-doped Si/SiGe for the p-legs. At higher temperatures the preferred quantum well legs are alternating layers of silicon and silicon carbide for the n-legs and for the p-legs alternating layers of different stoichiometric forms of B-C.

Quantum well thermoelectric power source

A super-lattice thermoelectric device. The device is comprised of p-legs and n-legs, each leg being comprised of a large number of very thin alternating layers of two materials with differing electron band gaps. The n-legs in the device are comprised of alternating layers of Si and SiC. The p-legs are comprised of alternating layers of BC and BC. In preferred embodiments the layers are about 100 angstroms thick. Thermoelectric modules made according to the present invention are useful for both cooling applications as well as electric power generation. This preferred embodiment is a thermoelectric 10&#xd7;10 egg crate type module about 6 cm&#xd7;6 cm&#xd7;0.76 cm designed to produce 70 Watts with a temperature difference of 300 degrees C. with a module efficiency of about 30 percent. The module has 98 active thermoelectric legs, with each leg having more than 3 million super-lattice layers.

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A super-lattice thermoelectric device. The device includes p-legs and n-legs, each leg having a large number of alternating layers of two materials with differing electron band gaps. The n-legs in the device are comprised of alternating layers of silicon and silicon germanium. The p-legs includes alternating layers of BC and BC. In preferred embodiments the layers are about 100 angstroms thick. Applicants have fabricated and tested a first Si/SiGe (n-leg) and BC/BC (p-leg) quantum well thermocouple. Each leg was only 11 microns thick on a 5 micron Si substrate. Nevertheless, in actual tests the thermocouple operated with an amazing efficiency of 14 percent with a Tof 250 degrees C. Thermoelectric modules made according to the present invention are useful for both cooling applications as well as electric power generation. This preferred embodiment is a thermoelectric 10&#xd7;10 egg crate type module about 6 cm&#xd7;6 cm&#xd7;0.76 cm designed to produce 70 Watts with a temperature difference of 300 degrees C with a module efficiency of about 30 percent.

Thermoelectric module with Si/SiGe and B4C/B9C super-lattice legs

Thermoelectric elements for use in a thermoelectric device. The thermoelectric elements have a very large number of alternating layers of semiconductor material deposited on a very thin organic substrate. The layers of semiconductor material alternate between barrier semiconductor material and conducting semiconductor material creating quantum wells within the thin layers of conducting semiconductor material. The conducting semiconductor material is doped to create conducting properties. The substrate preferably should be very thin, a very good thermal and electrical insulator with good thermal stability and strong and flexible.

Quantum well thermoelectric material on organic substrate

Thermoelectric elements for use in a thermoelectric device. The thermoelectric elements have a very large number of alternating layers of semiconductor material deposited on a very thin flexible substrate. The layers of semiconductor material alternate between barrier semiconductor material and conducting semiconductor material creating quantum wells within the thin layers of conducting semiconductor material. The conducting semiconductor material is doped to create conducting properties. The substrate preferably should be very thin, a very good thermal and electrical insulator with good thermal stability and strong and flexible. In a preferred embodiment, the thin organic substrate is a thin polyimide film (specifically Kapton.RTM.) coated with an even thinner film of crystalline silicon. The substrate is about 0.3 mills (127 microns) thick. The crystalline silicon layer is about 0.1 micron thick. This embodiment includes on each side of the thin Kapton.RTM. substrate about 3,000 alternating layers of silicon and silicon-germanium, each layer being about 100 .ANG. and the total thickness of the layers being about 30 microns. Preferably, the silicon layer is applied in an amorphous form and heated to about 350.degree. C. to 375.degree. C. to crystallize it. In other preferred embodiments, the substrate material is thin films of other organic materials or thin films of inorganic materials such as silicon.

Quantum well thermoelectric material on thin flexible substrate

A composition having an empirical formula MB.sub.2-z +N, wherein 0&lt;z&lt;0.10 and M is selected from the group consisting of Zr, Hf and Ti, wherein N is selected from a group consisting of Cu, Au and Ag and wherein the MB.sub.2-z defines a ceramic matrix structure defining a volume with void spaces comprising at least 10 percent of the volume of the matrix structure and the N occupies at least 70 percent, by volume, of the void spaces. A preferred method of making the composition is a two step process: First, ZrB.sub.2 powder (which preferably is slightly enriched in Zr is vacuum hot pressed at a hot pressing temperature of about 2150 degrees C. to create a ceramic matrix having a density of about 68 percent. Second, the ceramic matrix is heated in a pool of copper at a vacuum and at an infiltration temperature of about 1700 degrees C. to permit copper from the pool to infiltrate the ceramic matrix.

Metal infiltrated ceramic electrical conductor

A thermoelectric element having a very large number of alternating layers of semiconductor material. The alternating layers all have the same crystalline structure. The inventors have demonstrated that materials produced in accordance with this invention provide figures of merit more than six times that of prior art thermoelectric materials. A preferred embodiment is a superlattice of Si, as a barrier material, and SiGe, as a conducting material, both of which have the same cubic structure. Another preferred embodiment is a superlattice of B--C alloys, the layers of which would be different stoichiometric forms of B--C but in all cases the crystalline structure would be alpha 0. In a preferred embodiment the layers are grown under conditions as to cause them to be strained at their operating temperature range in order to improve the thermoelectric properties.

Superlattice quantum well material

A multi-layer superlattice quantum well thermoelectric material using materials for the layers having the same crystalline structure. A preferred embodiment is a superlattice of Si and SiGe, both of which have a cubic structure. Another preferred embodiment is a superlattice of B-C alloys, the layers of which would be different stoichometric forms of B-C but in all cases the crystalline structure would be alpha rhombohedral.

Growing community of inventors

La Jolla, CA, United States of America

Saeid Ghamaty