Mildred S Dresselhaus

US Patent:

6359288, Mar 19, 2002

Filed:

Apr 22, 1998

Appl. No.:

09/064242

Inventors:

Jackie Y. Ying - Winchester MA
Zhibo Zhang - Cambridge MA
Lei Zhang - Cambridge MA
Mildred S. Dresselhaus - Arlington MA

Assignee:

Massachusetts Institute of Technology - Cambridge MA

International Classification:

H01L 2915

US Classification:

257 14, 257 9, 257 28, 205202, 428606, 428614, 428629, 4284722

Abstract:

An array of nanowires having a relatively constant diameter and techniques and apparatus for fabrication thereof are described. In one embodiment, a technique for melting a material under vacuum and followed by pressure injection of the molten material into the pores of a porous substrate produces continuous nanowires. In another embodiment, a technique to systematically change the channel diameter and channel packing density of an anodic alumina substrate includes the steps of anodizing an aluminum substrate with an electrolyte to provide an anodic aluminum oxide film having a pore with a wall surface composition which is different than aluminum oxide and etching the pore wall surface with an acid to affect at least one of the surface properties of the pore wall and the pore wall composition.

US Patent:

6452206, Sep 17, 2002

Filed:

Mar 16, 1998

Appl. No.:

09/039602

Inventors:

Theodore C. Harman - Lexington MA
Mildred S. Dresselhaus - Arlington MA
David L. Spears - Acton MA
Michael P. Walsh - Lunenberg MA
Stephen B. Cronin - Cambridge MA
Xiangzhong Sun - Cambridge MA
Takaaki Koga - Cambridge MA

Assignee:

Massachusetts Institute of Technology - Cambridge MA

International Classification:

H01L 29225

US Classification:

257 22, 257 17, 257183, 257467, 257614, 257930

Abstract:

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.

US Patent:

6627809, Sep 30, 2003

Filed:

Nov 9, 2000

Appl. No.:

09/711160

Inventors:

Takaaki Koga - Kawagoo, JP
Mildred S. Dresselhaus - Arlington MA
Xiangzhong Sun - Westford MA
Steven B. Cronin - Cambridge MA

Assignee:

Massachusetts Institute of Technology - Cambridge MA

International Classification:

H01L 3512

US Classification:

1362361, 239240, 257 15

Abstract:

A carrier pocket engineering technique used to provide superlattice structures having relatively high values of the three-dimensional thermoelectric figure of merit (Z T) is described. Also described are several superlattice systems provided in acordance with the carrier pocket engineering technique. Superlattice structures designed in accordance with this technique include a plurality of alternating layers of at least two different semiconductor materials. First ones of the layers correspond to barrier layers and second ones of the layers correspond to well layers but barrier layers can also work as well layers for some certain carrier pockets and vice-versa. Each of the well layers are provided having quantum well states formed from carrier pockets at various high symmetry points in the Brillouin zone of the structure to provide the superlattice having a relatively high three-dimensional thermoelectric figure of merit.

US Patent:

7255846, Aug 14, 2007

Filed:

May 3, 2005

Appl. No.:

11/120725

Inventors:

Zhifeng Ren - Newton MA, US
Gang Chen - Carlisle MA, US
Bed Poudel - Watertown MA, US
Shankar Kumar - Watertown MA, US
Wenzhong Wang - Newton MA, US
Mildred Dresselhaus - Arlington MA, US

Assignee:

Massachusetts Institute of Technology - Cambridge MA
The Trustees of Boston College - Chestnut Hill MA

International Classification:

C01B 19/04
C01G 19/02
H01L 21/02
H01L 35/34

US Classification:

423508, 423509, 4235611, 423618, 977773, 977775, 977813, 977814, 252 623 T, 252 623 BT

Abstract:

The present invention provides methods for synthesis of IV–VI nanostructures, and thermoelectric compositions formed of such structures. In one aspect, the method includes forming a solution of a Group IV reagent, a Group VI reagent and a surfactant. A reducing agent can be added to the solution, and the resultant solution can be maintained at an elevated temperature, e. g. , in a range of about 20 C. to about 360 C. , for a duration sufficient for generating nanoparticles as binary alloys of the IV–VI elements.

US Patent:

7465871, Dec 16, 2008

Filed:

Oct 29, 2004

Appl. No.:

10/977363

Inventors:

Gang Chen - Carlisle MA, US
Zhifeng Ren - Newton MA, US
Mildred Dresselhaus - Arlington MA, US

Assignee:

Massachusetts Institute of Technology - Cambridge MA
The Trustees of Boston College - Chestnut Hill MA

International Classification:

H01L 35/12

US Classification:

1362361, 136238, 136239, 136240

Abstract:

The present invention is generally directed to nanocomposite thermoelectric materials that exhibit enhanced thermoelectric properties. The nanocomposite materials include two or more components, with at least one of the components forming nano-sized structures within the composite material. The components are chosen such that thermal conductivity of the composite is decreased without substantially diminishing the composite's electrical conductivity. Suitable component materials exhibit similar electronic band structures. For example, a band-edge gap between at least one of a conduction band or a valence band of one component material and a corresponding band of the other component material at interfaces between the components can be less than about 5kT, wherein kis the Boltzman constant and T is an average temperature of said nanocomposite composition.

US Patent:

7586033, Sep 8, 2009

Filed:

May 3, 2005

Appl. No.:

11/120729

Inventors:

Zhifeng Ren - Newton MA, US
Gang Chen - Carlisle MA, US
Bed Poudel - West Newton MA, US
Shankar Kumar - Newton MA, US
Wenzhong Wang - Beijing, CN
Mildred Dresselhaus - Arlington MA, US

Assignee:

Massachusetts Institute of Technology - Cambridge MA
The Trustees of Boston College - Chestnut Hill MA

International Classification:

C01B 25/14
C01B 19/00
H01L 35/16
H01L 35/22
H01L 35/14

US Classification:

136239, 136201, 136238, 1362361, 977813, 423508

Abstract:

The present invention generally relates to binary or higher order semiconductor nanoparticles doped with a metallic element, and thermoelectric compositions incorporating such nanoparticles. In one aspect, the present invention provides a thermoelectric composition comprising a plurality of nanoparticles each of which includes an alloy matrix formed of a Group IV element and Group VI element and a metallic dopant distributed within the matrix.

US Patent:

7875195, Jan 25, 2011

Filed:

Aug 1, 2007

Appl. No.:

11/832309

Inventors:

Oded Rabin - Cambridge MA, US
Paul R. Herz - San Diego CA, US
Mildred S. Dresselhaus - Arlington MA, US
Akintunde I. Akinwande - Newton MA, US
Yu-Ming Lin - White Plains NY, US

Assignee:

Massachusetts Institute of Technology - Cambridge MA

International Classification:

H01B 13/00

US Classification:

216 20, 216 31, 216 34, 216 35, 216 39, 430312, 430314, 313310, 313311, 313347, 313351, 313495

Abstract:

The presently disclosed invention provides for the fabrication of porous anodic alumina (PAA) films on a wide variety of substrates. The substrate comprises a wafer layer and may further include an adhesion layer deposited on the wafer layer. An anodic alumina template is formed on the substrate. When a rigid substrate such as Si is used, the resulting anodic alumina film is more tractable, easily grown on extensive areas in a uniform manner, and manipulated without danger of cracking. The substrate can be manipulated to obtain free-standing alumina templates of high optical quality and substantially flat surfaces. PAA films can also be grown this way on patterned and non-planar surfaces. Furthermore, under certain conditions, the resulting PAA is missing the barrier layer (partially or completely) and the bottom of the pores can be readily accessed electrically. The resultant film can be used as a template for forming an array of nanowires wherein the nanowires are deposited electrochemically into the pores of the template. By patterning the electrically conducting adhesion layer, pores in different areas of the template can be addressed independently, and can be filled electrochemically by different materials.

US Patent:

8168879, May 1, 2012

Filed:

Apr 28, 2009

Appl. No.:

12/431052

Inventors:

Gang Chen - Carlisle MA, US
Xiaoyuan Chen - Acton MA, US
Mildred Dresselhaus - Arlington MA, US
Zhifeng Ren - Newton MA, US

Assignee:

Massachusetts Institute of Technology - Cambridge MA

International Classification:

H01L 35/00
H01L 37/00

US Classification:

136206

Abstract:

Systems and methods utilizing solar-electrical generators are discussed. Solar-electrical generators are disclosed having a radiation-capture structure and one or more thermoelectric converters. Heat produced in a capture structure via impingement of solar radiation can maintain a portion of a thermoelectric converter at a high temperature, while the use of a low temperature at another portion allows electricity generation. Thus, unlike photovoltaic cells which are generally primarily concerned with optical radiation management, solar thermoelectrics converters are generally concerned with a variety of mechanisms for heat management. Generators can include any number of features including selective radiation surfaces, low emissivity surfaces, flat panel configurations, evacuated environments, and other concepts that can act to provide thermal concentration. Designs utilizing one or more optical concentrators are also disclosed.