Ultralow thermal conductivity via weak interactions in PbSe/PbTe monolayer heterostructure for thermoelectric design
In this study, we systematically investigate the thermal and electronic transport properties of a two-dimensional (2D) PbSe/PbTe monolayer heterostructure by combining first-principles calculations, Boltzmann transport theory, and machine learning methods. The heterostructure exhibits a unique honey...
| Autores: | , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2025 |
| País: | España |
| Institución: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:dnet:digitalcsic_::ead425f99332f786d0fbc42d7593a38e |
| Acceso en línea: | http://hdl.handle.net/10261/427356 |
| Access Level: | acceso abierto |
| Palabra clave: | Thermoelectric material First-principles calculations Lattice thermal conductivity Four-phonon scattering |
| Sumario: | In this study, we systematically investigate the thermal and electronic transport properties of a two-dimensional (2D) PbSe/PbTe monolayer heterostructure by combining first-principles calculations, Boltzmann transport theory, and machine learning methods. The heterostructure exhibits a unique honeycomb-like corrugated and asymmetric configuration, which significantly enhances phonon scattering. Moreover, the relatively weak interatomic interactions in PbSe/PbTe lead to the formation of antibonding states, resulting in strong anharmonicity and ultimately yielding ultralow lattice thermal conductivity (L). In the four-phonon scattering model, the (L) values along the x and y directions are as low as 0.37 and 0.31 W · m−1 · K−1, respectively. Contrary to the conventional view that long mean free path acoustic phonons dominate heat transport, we find that optical phonons contribute approximately 59 % of the in this heterostructure due to their larger group velocities than the acoustic phonons. Further analysis of thermoelectric performance shows that at a high temperature of 800 K, the heterostructure achieves an exceptional dimensionless figure of merit (ZT) of 5.3 along the y direction, indicating outstanding thermoelectric conversion efficiency. These findings not only provide theoretical insights into the transport mechanisms of PbSe/PbTe monolayer heterostructure but also offer a practical design strategy for developing high-performance 2D layered thermoelectric materials. |
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