High quality multifold Ge/Si/Ge composite quantum dots for thermoelectric materials
We present an effective approach to grow high-quality thin film of composite quantum dots (CQDs) as a building block for thermoelectric materials, in which 3 times the usual Ge deposition can be incorporated within a 3-fold CQD. Selective chemical etching experiments reveal that a thin Si inserted l...
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Veröffentlicht in: | Applied physics letters 2013-03, Vol.102 (10) |
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Hauptverfasser: | , , , , , |
Format: | Artikel |
Sprache: | eng |
Online-Zugang: | Volltext |
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Zusammenfassung: | We present an effective approach to grow high-quality thin film of composite quantum dots (CQDs) as a building block for thermoelectric materials, in which 3 times the usual Ge deposition can be incorporated within a 3-fold CQD. Selective chemical etching experiments reveal that a thin Si inserted layer in the CQDs modifies the growth mechanism through surface-mediated diffusion and SiGe alloying. Such thin-film-like CQD materials are demonstrated to exhibit reduced thermal conductivity κ⊥ with respect to the conventional QDs, perhaps as a consequence of enhanced diffusive phonon scattering from the high Si/Ge interface density and enhanced local alloying effect. |
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ISSN: | 0003-6951 1077-3118 |
DOI: | 10.1063/1.4794943 |