Massachusetts Institute of Technology

University of California

Theodore C Harman

Michael P Walsh

Patrick J Taylor

Mildred S Dresselhaus

Stephen B Cronin

Takaaki Koga

Xiangzhong Sun

Kang L Wang

David L Spears

Brian E LaForge

A thermoelectric (TE) device includes a first leg of TE material (a pseudobinary or pseudoternary alloy) and a second leg comprising a metal wire. The second leg is in thermal and electrical communication with the first leg. The TE device has a ZT value of approximately 2.0 at a temperature of approximately 300K.

Self-assembled quantum dot superlattice thermoelectric materials and devices

A test structure for testing a thick film thermoelectric device is presented. The test structure is able to test the thermoelectric device in the device's three modes of operation, namely as a cooling device, as a heat pump, and as a power generator. The test structure includes a pair of current electrode blocks for supporting and supplying power from a power supply to the thick film thermoelectric device being tested. Thermocouples are attached to different portions of the thick film thermoelectric device to indicate the temperature change across the device as it is being tested. Additionally, a heat source is provided when the device is being tested in an electrical generation mode. The test structure is able to compensate for the expansion and contraction of the thick film thermoelectric device during the testing. By way of the disclosed test structure, the thick film thermoelectric devices can be tested and characterized.

Thermoelectric device test structure

Quantum-dot superlattice (QLSL) structures having improved thermoelectric properties are described. In one embodiment, PbSe Te /PbTe QDSLs are provided having enhanced values of Seebeck coefficient and thermoelectric figure of merit (ZT) relative to bulk values. The structures can be combined into multi-chip devices to provide additional thermoelectric performance.

Nanostructured thermoelectric materials and devices

A superlattice structure for thermoelectric power generation includes m monolayers of a first barrier material alternating with n monolayers of a second quantum well material with a pair of monolayers defining a superlattice period and each of the materials having a relatively smooth interface therebetween. Each of the quantum well layers have a thickness which is less than the thickness of the barrier layer by an amount which causes substantial confinement of conduction carriers to the quantum well layer and the alternating layers provide a superlattice structure having a figure of merit which increases with increasing temperature.

Superlattice structures for use in thermoelectric devices

Quantum-dot superlattice (QLSL) structures having improved thermoelectric properties are described. In one embodiment, PbSe Te /PbTe QDSLs are provided having enhanced values of Seebeck coefficient and thermoelectric figure of merit (ZT) relative to bulk values.

Quantum dot thermoelectric materials and devices

A superlattice structure having a relatively high thermoelectric figure of merit and suitable for usage in power generation systems, and in heating and/or cooling applications is described. The superlattice structure includes a first plurality of layers formed from material D.sub.z J.sub.1-z, a second plurality of layers formed from material L.sub.x M.sub.1-x D.sub.z J.sub.1-z and a third plurality of layers formed from material L.sub.x M.sub.1-x D.sub.z J.sub.1-z wherein D is a non-metal chalcogen, and wherein J is a non-metal chalcogen, and wherein L is a group IV metal selected from the group of Pb, Sn, and Ge, and wherein M is a Group IV metal selected from the group of Pb, Sn, and Ge, and wherein D is not the same as J, and wherein L is not the same as M, and wherein 0.ltoreq.x.ltoreq.1 and 0.ltoreq.z.ltoreq.1.

Lead-chalcogenide superlattice structures

A superlattice structure for use in thermoelectric power generation systems includes m layers of a first one of Silicon and Antimony doped Silicon-Germanium alternating with n layers of Silicon-Germanium which provides a superlattice structure having a thermoelectric figure of merit which increases with increasing temperature above the maximum thermoelectric figure of merit achievable for bulk SiGe alloys.

Si/SiGe superlattice structures for use in thermoelectric devices

A superlattice structure comprising alternating layers of material such as (PbEuTeSe).sub.m and (BiSbn).sub.n where m and n are the number of PbEuTeSe and BiSb monolayers per superlattice period. For one superlattice structure the respective quantum barrier layers may be formed from electrical insulating material and the respective quantum well layers may be formed from semimetal material. For some applications superlattice structures with 10,000 or more periods may be grown. For example, the superlattice structure may comprise alternating layers of (Pb.sub.1-y Eu.sub.y Te.sub.1-z Se.sub.z).sub.m and (Bi.sub.x Sb.sub.1-x).sub.n. According to one embodiment, the superlattice structure may comprise a plurality of layers comprising m layers of (Pb.sub.1-y Eu.sub.y Te.sub.1-z Se.sub.z).sub.m and n layers of Bi.sub.0.9 Sb.sub.0.1, where m and n are preferably between 2 and 20, grown on a BaF.sub.2 substrate with a buffer layer of PbTe separating the substrate and the superlattice structure. For other applications the superlattice structure may be formed from alternating layers of (Pb.sub.1-y Eu.sub.y Te.sub.1-z Se.sub.z).sub.m (quantum barrier layers) and (Pb.sub.1-x Sn.sub.x Te.sub.1-y Se.sub.y).sub.n (quantum well layers)

Superlattice structures particularly suitable for use as thermoelectric

A superlattice comprising alternating layers of (PbTeSe).sub.m and (BiSb).sub.n (where m and n are the number of PbTeSe and BiSb monolayers per superlattice period, respectively) having engineered electronic structures for improved thermoelectric cooling materials (and other uses) may be grown by molecular beam epitaxial growth. Preferably, for short periods, n+m&lt;50. However, superlattice films with 10,000 or more such small periods may be grown. For example, the superlattice may comprise alternating layers of (PbTe.sub.1-z Se.sub.z).sub.m and (Bi.sub.x Sb.sub.1-x).sub.n. According to a preferred embodiment, the superlattice comprises a plurality of layers comprising m layers of PbTe.sub.0.8 Se.sub.0.2 and n layers of Bi.sub.0.9 Sb.sub.0.1, where m and n are preferably between 2 and 20.

Mercury cadmium telluride (Hg.sub.1-x Cd.sub.x Te) is formed from an atmosphere of mercury vapor maintained at a temperature of within about 1.degree. C. of a desired temperature which contacts a liquid cadmium-tellurium solution with or without mercury maintained at a temperature within about 1.degree. C. of a desired temperature. The resultant mercury-cadmium-tellurium solution then is cooled to solidification.

Growing community of inventors

Lexington, MA, United States of America

Theodore C Harman