Intrinsic carrier mobility of Dirac cones: The limitations of deformation potential theory
Intrinsic carrier mobility of Dirac cones: The limitations of deformation potential theory
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狄拉克锥的本征载流子迁移率：变形势理论的局限性
DOI：
10.1063/1.4897533
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发表时间：
2014-10-14
影响因子：
4.4
通讯作者：
Liu, Zhirong
中科院分区：
文献类型：
--
作者：
Li, Zhenzhu;Wang, Jinying;Liu, Zhirong
得到了二维体系（如石墨烯和石墨炔）声子散射条件下狄拉克锥本征载流子迁移率的解析公式。同时考虑了横向声子模式和纵向声子模式以及各向异性的影响。揭示了与变形势理论预测不同的一些特殊特征：中性点的迁移率与1/T-3成正比，其中T为温度；此外，TA声子的载流子散射在石墨烯的迁移率中占主导地位，这解释了之前实验中对石墨烯变形势测量的高估。该理论与第一性原理计算相结合，以确定石墨烯和五种具有狄拉克锥的石墨烯的迁移率。预测由于TA声子对散射的抑制，大多数石墨烯具有比石墨烯高得多的迁移率。(C) 2014 AIP出版有限责任公司
An analytic formula for the intrinsic carrier mobility of Dirac cones under acoustic phonon scattering conditions was obtained for 2D systems such as graphene and graphyne. The influences of both the transverse acoustic (TA) and longitudinal acoustic phonon modes and that of the anisotropy were considered. Some extraordinary characteristics unlike those predicted by the deformation potential theory were revealed: the mobility at the neutrality point is proportional to 1/T-3, where T is the temperature; also, carrier scattering by the TA phonons dominates the mobility of graphene, which explains the overestimation of the measured deformation potential of graphene in previous experiments. The theory was combined with first-principles calculations to determine the mobility of graphene and five graphynes with Dirac cones. It was predicted that most graphynes will have much higher mobility than graphene because of the suppression of the scattering by the TA phonons. (C) 2014 AIP Publishing LLC.