California Institute of Technology

Other

The United States of America As Represented by the Administrator of the

United States of America As Represented by the Administrator of Nasa

Thierry F Caillat

Jean-Pierre Fleurial

Alexander Borshchevsky

Alex Borshchevsky

G Jeffrey Snyder

Donald T Morelli

Gregory P Meisner

Elizabeth Kolawa

Margaret A Ryan

Peter Mueller

Leslie Zoltan

Andrew Zoltan

Wayne Phillips

Thorsten Kascich

Vilupanur Alwar Ravi

Samad A Firdosy

Eric W Jones

Jan W Vandersande

Marc C Foote

Jeffrey Snyder

Jong-Ah Paik

M Amy Ryan

N Thomas Olson

Billy Chun-Yip Li

Jeffrey S Sakamoto

Wayne M Philips

Harut Anjunyan

A thermoelectric power generation device is disclosed using one or more mechanically compliant and thermally and electrically conductive layers at the thermoelectric material interfaces to accommodate high temperature differentials and stresses induced thereby. The compliant material may be metal foam or metal graphite composite (e.g. using nickel) and is particularly beneficial in high temperature thermoelectric generators employing Zintl thermoelectric materials. The compliant material may be disposed between the thermoelectric segments of the device or between a thermoelectric segment and the hot or cold side interconnect of the device.

Compliant interfacial layers in thermoelectric devices

Alumina as a sublimation suppression barrier for a Zintl thermoelectric material in a thermoelectric power generation device operating at high temperature, e.g. at or above 1000K, is disclosed. The Zintl thermoelectric material may comprise YbMnSb. The alumina may be applied as an adhesive paste dried and cured on a substantially oxide free surface of the Zintl thermoelectric material and polished to a final thickness. The sublimation suppression barrier may be finalized by baking out the alumina layer on the Zintl thermoelectric material until it becomes substantially clogged with ytterbia.

Alumina paste sublimation suppression barrier for thermoelectric device

A method of applying a physical barrier to suppress thermal decomposition near a surface of a thermoelectric material including applying a continuous metal foil to a predetermined portion of the surface of the thermoelectric material, physically binding the continuous metal foil to the surface of the thermoelectric material using a binding member, and heating in a predetermined atmosphere the applied and physically bound continuous metal foil and the thermoelectric material to a sufficient temperature in order to promote bonding between the continuous metal foil and the surface of the thermoelectric material. The continuous metal foil forms a physical barrier to enclose a predetermined portion of the surface. Thermal decomposition is suppressed at the surface of the thermoelectric material enclosed by the physical barrier when the thermoelectric element is in operation.

Method of suppressing sublimation in advanced thermoelectric devices

The present invention is embodied in high performance p-type thermoelectric materials having enhanced thermoelectric properties and the methods of preparing such materials. In one aspect of the invention, p-type semiconductors of formula ZnASbBwherein 0&#x2266;x&#x2266;4, A is a transition metal, B is a pnicogen, and 0&#x2266;y&#x2266;3 are formed for use in manufacturing thermoelectric devices with substantially enhanced operating characteristics and improved efficiency. Two methods of preparing p-type ZnSband related alloys of the present invention include a crystal growth method and a powder metallurgy method.

High performance p-type thermoelectric materials and methods of preparation

A device for generating power to run an electronic component. The device includes a heat-conducting substrate (composed, e.g., of diamond or another high thermal conductivity material) disposed in thermal contact with a high temperature region. During operation, heat flows from the high temperature region into the heat-conducting substrate, from which the heat flows into the electrical power generator. A thermoelectric material (e.g., a BiTe alloy-based film or other thermoelectric material) is placed in thermal contact with the heat-conducting substrate. A low temperature region is located on the side of the thermoelectric material opposite that of the high temperature region. The thermal gradient generates electrical power and drives an electrical component.

Microfabricated thermoelectric power-generation devices

A high-efficiency thermoelectric unicouple is used for power generation. The unicouple is formed with a plurality of legs, each leg formed of a plurality of segments. The legs are formed in a way that equalizes certain aspects of the different segments. Different materials are also described.

Thermoelectric unicouple used for power generation

A class of thermoelectric compounds based on the skutterudite structure with heavy filling atoms in the empty octants and substituting transition metals and main-group atoms. High Seebeck coefficients and low thermal conductivities are achieved in combination with large electrical conductivities in these filled skutterudites for large ZT values. Substituting and filling methods are disclosed to synthesize skutterudite compositions with desired thermoelectric properties. A melting and/or sintering process in combination with powder metallurgy techniques is used to fabricate these new materials.

Thermoelectric devices based on materials with filled skutterudite structures

A high-efficiency thermoelectric unicouple is used for power generation. The unicouple is formed with a plurality of legs, each leg formed of a plurality of segments. The legs are formed in a way that equalized certain aspects of the different segments. Different materials are also described.

The present invention is embodied in high performance p-type thermoelectric materials having enhanced thermoelectric properties and the methods of preparing such materials. In one aspect of the invention, p-type semiconductors of formula Zn A Sb B wherein 0&lE;x&lE;4, A is a transition metal, B is a pnicogen, and 0&lE;y&lE;3 are formed for use in manufacturing thermoelectric devices with substantially enhanced operating characteristics and improved efficiency. Two methods of preparing p-type Zn Sb and related alloys of the present invention include a crystal growth method and a powder metallurgy method.

High performance P-type thermoelectric materials and methods of preparation

Thermoelectric materials with filled skutterudite structure for thermoelectric devices

A device for generating power to run an electronic component. The device includes a heat-conducting substrate (composed, e.g., of diamond or another high thermal conductivity material) disposed in thermal contact with a high temperature region. During operation, heat flows from the high temperature region into the heat-conducting substrate, from which the heat flows into the electrical power generator. A thermoelectric material (e.g., a Bi,Te,-based film or other thermoelectric material) is placed in thermal contact with the heat-conducting substrate. A low temperature region is located on the side of the thermoelectric material opposite that of the high temperature region. The thermal gradient generates electrical power and drives an electrical component.

Electronic device featuring thermoelectric power generation

Thermoelectric materials with filled skutterudite structure for

Linear arrays with up to 63 micromachined thermopile infrared detectors on silicon substrates have been constructed and tested. Each detector consists of a suspended silicon nitride membrane with 11 thermocouples of sputtered Bi--Te and Bi--Sb--Te thermoelectric elements films. At room temperature and under vacuum these detectors exhibit response times of 99 ms, zero frequency D* values of 1.4.times.10.sup.9 cmHz.sup.1/2 /W and responsivity values of 1100 V/W when viewing a 1000 K blackbody source. The only measured source of noise above 20 mHz is Johnson noise from the detector resistance. These results represent the best performance reported to date for an array of thermopile detectors. The arrays are well suited for uncooled dispersive point spectrometers. In another embodiment, also with Bi--Te and Bi--Sb--Te thermoelectric materials on micromachined silicon nitride membranes, detector arrays have been produced with D* values as high as 2.2.times.10.sup.9 cmHz.sup.1/2 /W for 83 ms response times.

Micromachined thermoelectric sensors and arrays and process for producing

Transition metals (T) of Group VIII (Co, Rh and Ir) have been prepared as semiconductor alloys with Sb, P, and As, having the general formula TX, wherein X is Sb.sub.3, P.sub.3, or As.sub.3. The skutterudite-type crystal lattice structure of these semiconductor alloys and their enhanced semiconductor properties results in semiconductor materials which may be used in the fabrication of power semiconductor devices to substantially improve the efficiency of the resulting semiconductor device. Semiconductor alloys having the desired skutterudite-type crystal lattice structure may be prepared in accordance with the present invention by using vertical gradient freeze techniques, liquid-solid phase sintering techniques, low temperature powder sintering and/or hot-pressing.

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Pasadena, CA, United States of America

Thierry F Caillat