Massachusetts Institute of Technology

The Trustees of Boston College

Other

Gmz Energy, Inc.

Bed Poudel

Zhifeng Ren

Gang Paul Chen

Mildred S Dresselhaus

Shankar Kumar

Shuo Chen

Xiao Yan

Wenzhong Wang

Xiaoyuan Chen

Dezhi Wang

James Christopher Caylor

Yucheng Lan

Bo Yu

Giri Joshi

Qing Hao

Yu Bo

Yi Ma

Xiaowei Wang

Joshi R Giri

Hsien-Ping Feng

Thermoelectric materials and methods of making thermoelectric materials having a nanometer mean grain size less than 1 micron. The method includes combining and arc melting constituent elements of the thermoelectric material to form a liquid alloy of the thermoelectric material and casting the liquid alloy of the thermoelectric material to form a solid casting of the thermoelectric material. The method also includes ball milling the solid casting of the thermoelectric material into nanometer mean size particles and sintering the nanometer size particles to form the thermoelectric material having nanometer scale mean grain size.

Half-heusler alloys with enhanced figure of merit and methods of making

Thermoelectric materials with high figures of merit, ZT values, are disclosed. In many instances, such materials include nano-sized domains (e.g., nanocrystalline), which are hypothesized to help increase the ZT value of the material (e.g., by increasing phonon scattering due to interfaces at grain boundaries or grain/inclusion boundaries). The ZT value of such materials can be greater than about 1, 1.2, 1.4, 1.5, 1.8, 2 and even higher. Such materials can be manufactured from a thermoelectric starting material by generating nanoparticles therefrom, or mechanically alloyed nanoparticles from elements which can be subsequently consolidated (e.g., via direct current induced hot press) into a new bulk material. Non-limiting examples of starting materials include bismuth, lead, and/or silicon-based materials, which can be alloyed, elemental, and/or doped. Various compositions and methods relating to aspects of nanostructured thermoelectric materials (e.g., modulation doping) are further disclosed.

Methods for high figure-of-merit in nanostructured thermoelectric materials

Methods of forming a conductive metal layers on substrates are disclosed which employ a seed layer to enhance bonding, especially to smooth, low-roughness or hydrophobic substrates. In one aspect of the invention, the seed layer can be formed by applying nanoparticles onto a surface of the substrate; and the metallization is achieved by electroplating an electrically conducting metal onto the seed layer, whereby the nanoparticles serve as nucleation sites for metal deposition. In another approach, the seed layer can be formed by a self-assembling linker material, such as a sulfur-containing silane material.

Metal deposition using seed layers

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.

Metal-doped semiconductor nanoparticles and methods of synthesis thereof

The present invention provides methods for synthesis of IV&#x2013;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&#xb0; C. to about 360&#xb0; C., for a duration sufficient for generating nanoparticles as binary alloys of the IV&#x2013;VI elements.

Methods for synthesis of semiconductor nanocrystals and thermoelectric compositions

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Brighton, MA, United States of America

Bed Poudel