Abstract
Enhancement of the Seebeck coefficient (S) without reducing the electrical conductivity () is essential to realize practical thermoelectric materials exhibiting a dimensionless figure of merit (ZT≤S2T1) exceeding 2, where T is the absolute temperature and is the thermal conductivity. Here, we demonstrate that a high-density two-dimensional electron gas (2DEG) confined within a unit cell layer thickness in SrTiO"3 yields unusually large |S|, approximately five times larger than that of SrTiO"3 bulks, while maintaining a high 2DEG. In the best case, we observe |S| = 850 μ V K-1 and 2DEG≤1.4×103Scm1. In addition, by using the of bulk single-crystal SrTiO"3 at room temperature, we estimate ZT2.4 for the 2DEG, corresponding to ZT0.24 for a complete device having the 2DEG as the active region. The present approach using a 2DEG provides a new route to realize practical thermoelectric materials without the use of toxic heavy elements.
Original language | English |
---|---|
Pages (from-to) | 129-134 |
Number of pages | 6 |
Journal | Nature Materials |
Volume | 6 |
Issue number | 2 |
DOIs | |
Publication status | Published - 2007 Feb |
Externally published | Yes |
ASJC Scopus subject areas
- Chemistry(all)
- Materials Science(all)
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering