title: High-quality graphene p-n junctions via resist-free fabrication and solution-based noncovalent functionalization.
abstract: An essential issue in graphene nanoelectronics is to engineer the carrier type and density and still preserve the unique band structure of graphene. We report the realization of high-quality graphene p-n junctions by noncovalent chemical functionalization. A generic scheme for the graphene p-n junction fabrication is established by combining the resist-free approach and spatially selective chemical modification process. The effectiveness of the chemical functionalization is systematically confirmed by surface topography and potential measurements, spatially resolved Raman spectroscopic imaging, and transport/magnetotransport measurements. The transport characteristics of graphene p-n junctions are presented with observations of high carrier mobilities, Fermi energy difference, and distinct quantum Hall plateaus. The chemical functionalization of graphene p-n junctions demonstrated in this study is believed to be a feasible scheme for modulating the doping level in graphene for future graphene-based nanoelectronics.
authors.affiliation: Institute of Atomic and Molecular Sciences, Academia Sinica, P.O. Box 23-166, Taipei 106, Taiwan.
authors.forename: Hung-Chieh
authors.initials: HC
authors.lastname: Cheng
authors.forename: Ren-Jye
authors.initials: RJ
authors.lastname: Shiue
authors.forename: Chia-Chang
authors.initials: CC
authors.lastname: Tsai
authors.forename: Wei-Hua
authors.initials: WH
authors.lastname: Wang
authors.forename: Yit-Tsong
authors.initials: YT
authors.lastname: Chen
mesh_terms: D004566:Electrodes; 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; D012996:Solutions
chemical_list: D012996:Solutions; D006108:Graphite