Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7933086 | Physica E: Low-dimensional Systems and Nanostructures | 2018 | 5 Pages |
Abstract
It is known that the figure of merit (ZT) of thin nanowires can be significantly enhanced at room temperature due to the reduction of phonon thermal conductance arising from the increase of boundary scattering of phonons. It is expected that the phonon thermal conductance of nanowires filled with quantum dots (QDs) will be further reduced. Here we consider a superlattice nanowire (SLNW) modeled by a linear chain of strongly coupled QDs connected to electrodes. We study the dependence of ZT on the QD energy level (E0) (relative to the Fermi level EF in the electrodes), inter-dot coupling strength (tc), tunneling rate (Î), and temperature T in order to optimize the design. It is found that at room temperature the maximum power factor occurs when (E0â¯ââ¯EF)âkBTâ¯ââ¯2.4 and Îâ¯=â¯tc, a result almost independent of the number of QDs in SLNW as long as tcâkBTâ¯<â¯0.5. By using reasonable physical parameters we show that thin SLNW with cross-sectional width near 3â¯nm has a potential to achieve ZTâ¯â¥â¯3.
Keywords
Related Topics
Physical Sciences and Engineering
Materials Science
Electronic, Optical and Magnetic Materials
Authors
David M.T. Kuo, C.C. Chen, Yia-Chung Chang,