Charge trapping and scattering in epitaxial graphene
Charge trapping and scattering in epitaxial graphene
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DOI：
10.1103/physrevb.84.205417
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发表时间：
2011-11-14
影响因子：
3.7
通讯作者：
Avouris, Phaedon
中科院分区：
文献类型：
--
作者：
Farmer, Damon B.;Perebeinos, Vasili;Avouris, Phaedon
外延石墨烯的霍尔迁移率和相应的载流子密度表现出出乎意料的强烈温度依赖性。这种行为归因于碳化硅衬底中的电荷陷阱，其特征结合能约为70兆电子伏。研究了与这些陷阱相关的静电筛选和相应的载流子输运行为，以及在迁移率急剧增加的低密度下的输运。高载流子密度下的迁移率可以通过库仑散射和短程散射得到满意的描述。在低密度状态下，长波长范围内的散射体透明会导致迁移率的突然增加。
The Hall mobility and corresponding density of charge carriers in epitaxial graphene exhibit unexpectedly strong temperature dependence. This behavior is attributed to charge traps in the silicon carbide substrate that have a characteristic binding energy of approximately 70 meV. The electrostatic screening associated with these traps and the corresponding carrier transport behavior are investigated, as is transport at low densities, where the mobility sharply increases. The mobility at high carrier densities can be satisfactorily described by invoking Coulomb and short-range scattering. Scatterer transparency in the long-wavelength limit is suggested to occur in the low density regime, resulting in an abrupt mobility increase.