• 文献标题:   Pulse Dynamics of Electric Double Layer Formation on All-Solid-State Graphene Field-Effect Transistors
  • 文献类型:   Article
  • 作  者:   XU K, ISLAM MM, GUZMAN D, SEABAUGH AC, STRACHAN A, FULLERTONSHIREY SK
  • 作者关键词:   electric double layer, fieldeffect transistor, edlt, molecular dynamic, graphene, solid polymer electrolyte, ion transport, iontronic
  • 出版物名称:   ACS APPLIED MATERIALS INTERFACES
  • ISSN:   1944-8244
  • 通讯作者地址:   Univ Pittsburgh
  • 被引频次:   2
  • DOI:   10.1021/acsami.8b13649
  • 出版年:   2018

▎ 摘  要

Electric double layer (EDL) dynamics in graphene field-effect transistors (FETs) gated with polyethylene oxide (PEO)-based electrolytes are studied by molecular dynamics (MD) simulations from picoseconds to nanoseconds and experimentally from microseconds to milliseconds. Under an applied field of approximately mV/nm, EDL formation on graphene FETs gated with PEO:CsClO4 occurs on the timescale of microseconds at room temperature and strengthens within 1 ms to a sheet carrier density of n(s) approximate to 10(13) cm(-2). Stronger EDLs (i.e., larger n(s)) are induced experimentally by pulsing with applied voltages exceeding the electrochemical window of the electrolyte; electrochemistry is avoided using short pulses of a few milliseconds. Dynamics on picosecond to nanosecond timescales are accessed using MD simulations of PEO:LiClO4 between graphene electrodes with field strengths of hundreds of mV/nm which is 100x larger than experiment. At 100 mV/nm, EDL formation initiates in sub-nanoseconds achieving charge densities up to 6 x 10(13) cm(-2) within 3 nanoseconds. The modeling shows that under sufficiently high electric fields, EDLs with densities similar to 10(13) cm(-2) can form within a nanosecond, which is a timescale relevant for high-performance electronics such as EDL transistors (EDLTs). Moreover, the combination of experiment and modeling shows that the timescale for EDL formation (n(s) = 10(13) to 10(14) cm(-2)) can be tuned by 9 orders of magnitude by adjusting the field strength by only 3 orders of magnitude.