US5415699A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Superlattice structures particularly suitable for use as thermoelectric cooling materials
Assignee: Massachusetts Institute of Technology
•
Filing: 1993-01-12
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Granted: 1995-05-16
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Expires: 2013-01-12
Abstract
Abstract A superlattice comprising alternating layers of (PbTeSe) m and (BiSb) 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<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 1-z Se z ) m and (Bi x Sb 1-x ) n . According to a preferred embodiment, the superlattice comprises a plurality of layers comprising m layers of PbTe 0 .8 Se 0 .2 and n layers of Bi 0 .9 Sb 0 .1, where m and n are preferably between 2 and 20.
Inventors
- 👤 Theodore Harman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 15:56
CPC Classifications
H; H10; H10N; H10N10/00; H10N10/80; H10N10/85; H10N10/851; H10N10/852; Y; Y10; Y10S; Y10S257/00; Y10S257/93
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
65 words
A superlattice comprising a plurality of alternating layers of a first material comprising D z J 1-z and a second material comprising Bi; where D is a Group VI non-metal selected from the group consisting of Te, Se and S; J is a Group VI non-metal selected from the group consisting of Te, Se and S; D is not the same as J; and 0≦z≦1.
Claim 2
Dependent Claim
65 words
A superlattice comprising a plurality of alternating layers of a first material comprising D z J 1-z and a second material comprising Bi; where D is a Group VI non-metal selected from the group consisting of Te, Se and S; J is a Group VI non-metal selected from the group consisting of Te, Se and S; D is not the same as J; and 0≦z≦1.
Claim 3
Dependent Claim
24 words
The superlattice of claim 1 having an energy gap between 0 kT and 10 kT: where k is Boltzman's constant and T is temperature.
Claim 4
Dependent Claim
50 words
The superlattice of claim 1 having at least one of the following properties: a density of states effective mass less than 0.05; a lattice thermal conductivity less than 10 mWcm -1 K -1 and a materials factor (b*) greater than 40,000 cm 3 kW -1 V -1 S -1 .
Claim 5
Dependent Claim
14 words
The superlattice of claim 1 having thermoelectric figure of merit greater than approximately 1.7.
Claim 6
Dependent Claim
15 words
The superlattice of claim 1 having a thermoelectric figure of merit greater than approximately 2.0.
Claim 7
Dependent Claim
15 words
The superlattice of claim 1 having a thermoelectric figure of merit greater than approximately 2.5.
Claim 8
Dependent Claim
15 words
The superlattice of claim 1 having a thermoelectric figure of merit greater than approximately 3.0.
Claim 9
Dependent Claim
15 words
The superlattice of claim 1 having a thermoelectric figure of merit approximately equal to 3.2.
Claim 10
Dependent Claim
120 words
The superlattice of claim 1 wherein the layer thickness of the respective first and second materials and the number of layers of the first and second materials within a period of the superlattice are formed such that E g sl is approximately in the range of 0 kT to 8 kT, where k is Boltzman's constant, T is temperature and E g sl ={E gA d A +E gB d B }/(d A +d B ); where E g sl is the energy gap of the superlattice, E gA and E gB are the energy gaps of the first and second materials, respectively, and d A and d B are the layer thicknesses of the first and second materials, respectively.
Claim 11
Dependent Claim
28 words
A superlattice comprising a predetermined number of alternating layers of two component materials, where one of the component materials comprises TeSe and the other component material comprises Bi.
Claim 12
Dependent Claim
28 words
A superlattice comprising a predetermined number of alternating layers of two component materials, where one of the component materials comprises TeSe and the other component material comprises Bi.
Claim 13
Dependent Claim
25 words
A thermoelectric module comprising: a plurality of thermoelectric chips which are stacked and bonded, wherein said thermolectric chips comprise a superlattice according to claim 1.
Claim 14
Dependent Claim
31 words
A thermoelectric device comprising: an n-type leg; a second leg operatively connected to said n-type leg for thermoelectric cooling; wherein said n-type leg comprises a thermoelectric module according to claim 11.
Claim 15
Dependent Claim
15 words
A thermoelectric device according to claim 12 wherein said second leg comprises a p-type leg.
Claim 16
Dependent Claim
15 words
A thermoelectric device according to claim 12 wherein said second leg comprises a superconductor material.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1998-05-15 | 1998-11-14 | 1999-05-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-05-15 | 2002-11-14 | 2003-05-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-05-15 | 2006-11-14 | 2007-05-16 | $7700.00 | Window Closed / Lapsed |