Epitaxial graphene homogeneity and quantum Hall effect in millimeter-scale devices

Yanfei Yang; Guangjun Cheng; Patrick Mende; Irene G. Calizo; Randall M. Feenstra; Chiashain Chuang; Chieh-Wen Liu; Chieh-I Liu; George R. Jones; Angela R. Hight Walker; Randolph E. Elmquist

arXiv · 1606.07720

Epitaxial graphene homogeneity and quantum Hall effect in millimeter-scale devices

Yanfei Yang·Guangjun Cheng·Patrick Mende·Irene G. Calizo·Randall M. Feenstra·Chiashain Chuang·Chieh-Wen Liu·Chieh-I Liu·George R. Jones·Angela R. Hight Walker·Randolph E. Elmquist

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Abstract

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 {\deg}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.

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Yanfei Yang, Guangjun Cheng, Patrick Mende, Irene G. Calizo, Randall M. Feenstra, Chiashain Chuang, Chieh-Wen Liu, Chieh-I Liu, George R. Jones, Angela R. Hight Walker, Randolph E. Elmquist. 2016-06-24. Epitaxial graphene homogeneity and quantum Hall effect in millimeter-scale devices. https://arxiv.org/abs/1606.07720

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