arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1607.03037cond-mat.mtrl-scicond-mat.mes-hall
收藏

石墨烯的电子热导率

The electronic thermal conductivity of graphene

Tae Yun Kim, Cheol-Hwan Park, Nicola Marzari

备注：
5 pages 6 figures
发表信息：
Nano Lett. 16, 2439-2443 (2016)
阅读 PDF
arXiv 页面 ↗HTML 原文 ↗

摘要：

石墨烯作为一种已知热导率最大的半金属，是研究电子和晶格对热输运的贡献之间相互作用的理想体系。虽然总的电导率和热导率已被广泛研究，但其电子热导率的详细第一性原理研究仍然缺失。在这里，我们首先使用电子和声子色散和电子-声子耦合计算的第一性原理在密度泛函理论和多体微扰理论（GW）的水平上的电子-声子固有的贡献，作为掺杂的石墨烯的电子热阻率的函数。然后，我们包括非本征电子杂质散射使用低温实验估计。在这些条件下，我们发现掺杂石墨烯的面内电子热导率在室温下为~300 W/mK，与掺杂无关。这一结果比预期的要大得多，并且与典型金属的总热导率相当，对块状石墨烯的总热导率贡献约10%。值得注意的是，在样品的物理或域的大小是几微米或更小的顺序，来自电子热导率的相对贡献是更重要的比在散装限制，因为晶格热导率是更敏感的样品或晶粒尺寸在这些尺度。最后，当考虑电子-杂质散射效应时，我们发现电子热导率降低了30%到70%。我们还发现，Wiedemann-Franz定律在低温和高温下都是广泛满足的，但在室温附近的最大偏差为20- 50%。

英文摘要：

Graphene, as a semimetal with the largest known thermal conductivity, is an ideal system to study the interplay between electronic and lattice contributions to thermal transport. While the total electrical and thermal conductivity have been extensively investigated, a detailed first-principles study of its electronic thermal conductivity is still missing. Here, we first characterize the electron-phonon intrinsic contribution to the electronic thermal resistivity of graphene as a function of doping using electronic and phonon dispersions and electron-phonon couplings calculated from first principles at the level of density-functional theory and many-body perturbation theory (GW). Then, we include extrinsic electron-impurity scattering using low-temperature experimental estimates. Under these conditions, we find that the in-plane electronic thermal conductivity of doped graphene is ~300 W/mK at room temperature, independently of doping. This result is much larger than expected, and comparable to the total thermal conductivity of typical metals, contributing ~10 % to the total thermal conductivity of bulk graphene. Notably, in samples whose physical or domain sizes are of the order of few micrometers or smaller, the relative contribution coming from the electronic thermal conductivity is more important than in the bulk limit, since lattice thermal conductivity is much more sensitive to sample or grain size at these scales. Last, when electron-impurity scattering effects are included, we find that the electronic thermal conductivity is reduced by 30 to 70 %. We also find that the Wiedemann-Franz law is broadly satisfied at low and high temperatures, but with the largest deviations of 20-50 % around room temperature.

机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。

↑