title: Electrochemical gate-controlled charge transport in graphene in ionic liquid and aqueous solution.
abstract: We have studied the electron transport behavior of electrochemically gated graphene transistors in different solutions. In an ionic liquid, we have determined the electron and hole carrier densities and estimated the concentration of charged impurities to be (1-10) x 10(12) cm(-2). The minimum conductivity displays an exponential decrease with the density of charged impurities, which is attributed to the impurity scattering of the carriers. In aqueous solutions, the position of minimum conductivity shifts negatively as the ionic concentration increases. The dependence of the transport properties on ionic concentration is important for biosensor applications, and the observation is modeled in terms of screening for impurity charges by the ions in solutions.
authors: Center for Bioelectronics and Biosensors, Biodesign Institute, Department of Electrical Engineering, Arizona State University, Tempe, Arizona 85287, USA.
authors: Fang
authors: F
authors: Chen
authors: Quan
authors: Q
authors: Qing
authors: Jilin
authors: J
authors: Xia
authors: Jinghong
authors: J
authors: Li
authors: Nongjian
authors: N
authors: Tao
mesh_terms: D004553:Electric Conductivity; D004563:Electrochemistry; D006108:Graphite / Q000737:chemistry*; D007093:Imidazoles / Q000737:chemistry*; D052578:Ionic Liquids / Q000737:chemistry*; D012996:Solutions; D014867:Water / Q000737:chemistry
chemical_list: C412621:1-butyl-3-methylimidazolium hexafluorophosphate; D007093:Imidazoles; D052578:Ionic Liquids; D012996:Solutions; D014867:Water; D006108:Graphite