毫米级器件中外延石墨烯的均匀性和量子霍尔效应
Epitaxial graphene homogeneity and quantum Hall effect in millimeter-scale devices
摘要：
在5.6 x 5.6 mm^2外延石墨烯器件中观察到量子化的磁输运，该器件在高温（1900 °C）下使用SiC（0001）的Si面上的高度约束升华生长。精确的量子化霍尔电阻Rxy = h/2e^2在T = 3.1 K和9 T时保持在临界电流Ixx = 0.72 mA的最高记录水平，拉曼显微镜显示出低而均匀的应变。在第二个器件中，吸附诱导的分子掺杂降低了载流子浓度，接近狄拉克点（n ~ 1 E10（1/cm^2）），在10 mm^2的面积上测得迁移率为43700 cm^2/Vs。原子力，共聚焦光学，和拉曼显微镜被用来表征大规模的设备，并揭示了改进的SiC平台形貌和石墨烯层的结构。我们的研究结果表明，通过面石墨加工生产的外延石墨烯的结构均匀性有助于毫米级的输运均匀性，并将证明对科学和商业应用有用。
英文摘要：
Quantized magnetotransport is observed in 5.6 x 5.6 mm^2 epitaxial graphene devices, grown using highly constrained sublimation on the Si-face of SiC(0001) at high temperature (1900 °C). The precise quantized Hall resistance of Rxy = h/2e^2 is maintained up to record level of critical current Ixx = 0.72 mA at T = 3.1 K and 9 T in a device where Raman microscopy reveals low and homogeneous strain. Adsorption-induced molecular doping in a second device reduced the carrier concentration close to the Dirac point(n ~ 1E10 (1/cm^2)), where mobility of 43700 cm^2/Vs is measured over an area of 10 mm^2. Atomic force, confocal optical, and Raman microscopies are used to characterize the large-scale devices, and reveal improved SiC terrace topography and the structure of the graphene layer. Our results show that the structural uniformity of epitaxial graphene produced by face-to-graphite processing contributes to millimeter-scale transport homogeneity, and will prove useful for scientific and commercial applications.
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。
