Unusually Large Enhancement of Thermopower in an Electric Field InducedTwo-Dimensional Electron Gas
| Autor: | Kenji Nomura, Yuichi Ikuhara, Shijian Zheng, Hideo Hosono, Hideya Kumomi, Taku Mizuno, Takeharu Kato, Hiromichi Ohta, Katsumi Abe |
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| Jazyk: | angličtina |
| Rok vydání: | 2012 |
| Předmět: |
Condensed Matter - Materials Science
Materials science Condensed matter physics Nanoporous Mechanical Engineering Temperature Materials Science (cond-mat.mtrl-sci) FOS: Physical sciences Electrons Electron Thermoelectric materials Crystal Electric Power Supplies Mechanics of Materials Seebeck coefficient Electric field General Materials Science Field-effect transistor Gases Fermi gas |
| Zdroj: | Advanced. Materials. 24:740-744 |
| Popis: | Two-dimensionally confined electrons showing unusually large thermopower (S) have attracted attention as a potential approach for developing high performance thermoelectric materials. However, enhanced S has never been observed in electric field induced two-dimensional electron gas (2DEG). Here we demonstrate electric field modulation of S for a field effect transistor (FET) fabricated on a SrTiO3 crystal using a water-infiltrated nanoporous glass as the gate insulator. An electric field application confined carrier electrons up to ~2E15 /cm^2 in an extremely thin (~2 nm) 2DEG. Unusually large enhancement of |S| was observed when the sheet carrier concentration exceeded 2.5E14 /cm^2, and it modulated from ~600 (~2E15 /cm^2) to ~950 {\mu}V/K (~8E14 /cm^2), which were approximately five times larger than those of the bulk, clearly demonstrating that an electric field induced 2DEG provides unusually large enhancement of |S|. Comment: 20 pages including 4 figures and Supporting Information, Advanced Materials (in press) |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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