tailieunhanh - Báo cáo hóa học: " Modeling Electrolytically Top-Gated Graphe"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Modeling Electrolytically Top-Gated Graphe | Nanoscale Res Lett 2010 5 505-511 DOI s11671-009-9515-3 SPECIAL ISSUE ARTICLE Modeling Electrolytically Top-Gated Graphene Z. L. MiskoviC Nitin Upadhyaya Received 12 August 2009 Accepted 14 December 2009 Published online 7 January 2010 The Author s 2010. This article is published with open access at Abstract We investigate doping of a single-layer graphene in the presence of electrolytic top gating. The interfacial phenomenon is modeled using a modified Poisson-Boltzmann equation for an aqueous solution of simple salt. We demonstrate both the sensitivity of graphene s doping levels to the salt concentration and the importance of quantum capacitance that arises due to the smallness of the Debye screening length in the electrolyte. Keywords Graphene Electrolyte Poisson-Boltzmann model Gating Quantum capacitance Introduction Carbon nano-structures show great promise in many applications including chemical and biological sensors. While carbon nanotubes CNTs have been extensively studied in that context for quite some time 1 2 investigations of graphene as a sensor are only beginning to appear 3-5 . Sensory function of carbon nano-structures is generally implemented in the configuration of a field effect transistor FET with a prominent role played by the gate potential that controls the current through the device. Biochemical applications require good understanding of the interaction of carbon nano-structures with aqueous solutions 5 often in the context of the electrochemical top gating 6 . While significant progress has been achieved in understanding the interaction of CNT-FETs Z. L. Miskovic El N. Upadhyaya Department of Applied Mathematics University of Waterloo Waterloo ON n2L 3G1 Canada e-mail zmiskovi@ with the electrolytic environment 7-9 similar studies involving graphene have appeared only very recently 6 focusing on the screening effect of an ion solution on charge transport through graphene-based FETs 10 as well as on the