Experimental study of thermal conductivity reduction of silicon-germanium nanocomposite for thermoelastic application

To improve the thermoelectric energy conversion efficiency of silicon germanium (SiGe), two methods were used to decrease the thermal conductivity by increasing phonon boundary scattering at interfaces. In the first method, SiGe alloys were annealed at a temperature higher than the melting point to increase the number of grain boundaries. In the second method, SiGe composites were made with nanosize silicon particles. For annealed SiGe alloys thermal conductivity decreased by a factor of two while power factor remained the same value. For SiGe nanocomposite thermal conductivity decreased by a factor of four to that of bulk alloy, but electrical conductivity deteriorated. Future work will focus on increasing electrical conductivity while reducing the thermal conductivity.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Mechanical Engineering.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2005

Author dc:creator

• Lee, Hohyun, 1978-

Advisor dc:contributor.advisor

• Gang Chen.

• Mechanical Engineering.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/30311

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/30311