Thermal conductivity for III-V and II-VI semiconductor wurtzite and zinc-blende polytypes
We calculate the lattice thermal conductivity (κ) for cubic (zinc-blende) and hexagonal (wurtzite) phases for eight semiconductors using ab initio calculations and solving the phonon Boltzmann transport equation, explaining the different behavior of the ratio κhex/κcub between the two phases. We sho...
| Autores: | , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2019 |
| País: | España |
| Institución: | Universitat Autònoma de Barcelona |
| Repositorio: | Dipòsit Digital de Documents de la UAB |
| Idioma: | inglés |
| OAI Identifier: | oai:ddd.uab.cat:292896 |
| Acceso en línea: | https://ddd.uab.cat/record/292896 https://dx.doi.org/urn:doi:10.1103/PhysRevMaterials.3.084607 |
| Access Level: | acceso abierto |
| Palabra clave: | Heat transfer Lattice thermal conductivity Phonons Thermal conductivity Thermal properties |
| Sumario: | We calculate the lattice thermal conductivity (κ) for cubic (zinc-blende) and hexagonal (wurtzite) phases for eight semiconductors using ab initio calculations and solving the phonon Boltzmann transport equation, explaining the different behavior of the ratio κhex/κcub between the two phases. We show that this behavior depends on the relative importance of two antagonistic factors: anharmonicity, which we find to be always higher in the cubic phase, and the accessible phase space, which is higher for the less symmetric hexagonal phase. Based on that, we develop a method that predicts the most conducting phase - cubic or hexagonal - where other more heuristic approaches fail. We also present results for nanowires made of the same materials, showing the possibility to tune κhex/κcub over a wide range by modifying their diameter, thus making them attractive materials for complex phononic and thermoelectric applications and systems. |
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