Epitaxial graphene homogeneity and quantum Hall effect in millimeter-scale devices. (May 2017)

• Record Type: Journal Article
• Authors: Yang, Yanfei; Cheng, Guangjun; Mende, Patrick; Calizo, Irene G.; Feenstra, Randall M.; Chuang, Chiashain; Liu, Chieh-Wen; Liu, Chieh-I.; Jones, George R.; Hight Walker, Angela R.; Elmquist, Randolph E.
• Is Part Of: Carbon. Volume 115(2017)
• Page Start: 229
• Page End: 236
• Publication Date: 2017-05
• Subjects: Epitaxial graphene -- Transport mobility -- Carrier density -- Adsorption-induced molecular doping -- Strain -- Low-energy electron microscopy -- Raman microscopy -- Quantized Hall effect; Carbon -- Periodicals; Carbone -- Périodiques; Koolstof; Toepassingen; Electronic journals; 546.681
• DOI: 10.1016/j.carbon.2016.12.087
• Languages: English
• ISSNs: 0008-6223

Abstract

Abstract: Quantized magnetotransport is observed in 5.6 × 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 R x y = h 2 e 2 is maintained up to record level of critical current I xx = 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 ≈ 10 10 cm −2 ), where mobility of 18760 cm 2 /V 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. Graphical abstract: