Ab initio optimization of phonon drag effect for lower-temperature thermoelectric energy conversion

• Main Authors: Zhou, Jiawei (Contributor), Liao, Bolin (Contributor), Qiu, Bo (Contributor), Huberman, Samuel C. (Contributor), Esfarjani, Keivan (Contributor), Dresselhaus, Mildred (Contributor), Chen, Gang (Contributor)
• Other Authors: Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science (Contributor), Massachusetts Institute of Technology. Department of Mechanical Engineering (Contributor), Massachusetts Institute of Technology. Department of Physics (Contributor)
• Format: Article
• Language: English
• Published: National Academy of Sciences (U.S.), 2017-07-06T17:58:13Z.
• Subjects: Article
• Online Access: Get fulltext

It has been well known that the phonon drag effect-an extra electrical current induced by phonon heat flow via electron-phonon interaction-can lead to unusually high Seebeck coefficient at low temperatures. However, its use for improving thermoelectric performance has been controversial. Here, using first principles calculations we examine the phonon drag with detailed mode-specific contributions and reveal that even in heavily doped silicon at room temperature, phonon drag can still be significant, which challenges the previous belief that phonon drag vanishes in heavily doped samples. A phonon filter is designed to spectrally decouple the phonon drag from the heat conduction. Our simulation explores the coupled electron phonon transport and uncovers the possibility of optimizing the phonon drag for better thermoelectrics.
United States. Department of Energy. Office of Science. Solid-State Solar Thermal Energy Conversion Center (Award DE- SC0001299/DE-FG02-09ER46577)
United States. Air Force. Office of Scientific Research. Multidisciplinary University Research Initiative (AFOSR MURI FA9550-10-1-0533)