title: Investigation of transfer characteristics of high performance graphene flakes.
abstract: In this article, we attempted a study on field effect transport characteristics of graphene flakes. These graphene flakes were exfoliated by mechanical peeling-off technique and the electrical contacts were patterned by photo-lithographic method. Graphene devices have shown better transfer characteristics which was obtained even in low-voltage (< 5 V). Back-gated graphene transistors were patterned on oxidized silicon wafers. A clear n-type to p-type transition at Dirac point and higher electron drain-current modulation in positive back-gate field with current minimum (the Dirac point) were observed at V(GS) = -1.7 V. The carrier mobility was determined from the measured transconductance. The transconductance of the graphene transistors was observed as high as 18.6 microS with a channel length of 68 microm. A maximum electron mobility of 1870 +/- 143 cm2/V x s and hole mobility of 1050 +/- 35 cm2/V x s were achieved at a drain bias 2.1 V which are comparatively higher values among reported for mechanically exfoliated graphene using lithographic method. The fabricated devices also sustained with high-current density for 40 hr in continuous operation without any change in device resistance, which could be applied for robust wiring applications.
authors.affiliation: Department of Nanoscience and Technology, Karunya University, Coimbatore 641114, Tamil Nadu, India.
authors.forename: Gunasekaran
authors.initials: G
authors.lastname: Venugopal
authors.forename: Karthikeyan
authors.initials: K
authors.lastname: Krishnamoorthy
authors.forename: Sang-Jae
authors.initials: SJ
authors.lastname: Kim
mesh_terms: D004579:Electron Transport; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006108:Graphite / Q000737:chemistry*; D008422:Materials Testing; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D010316:Particle Size; D012666:Semiconductors
chemical_list: D006108:Graphite