• 文献标题:   Fabrication of Unipolar Graphene Field-Effect Transistors by Modifying Source and Drain Electrode Interfaces with Zinc Porphyrin
  • 文献类型:   Article
  • 作  者:   KHADERBAD MA, TJOA V, RAO M, PHANDRIPANDE R, MADHU S, WEI J, RAVIKANTH M, MATHEWS N, MHAISALKAR SG, RAO VR
  • 作者关键词:   graphene, transistor, unipolar, selfassembled monolayer, injection barrier
  • 出版物名称:   ACS APPLIED MATERIALS INTERFACES
  • ISSN:   1944-8244
  • 通讯作者地址:   Nanyang Technol Univ
  • 被引频次:   13
  • DOI:   10.1021/am201691s
  • 出版年:   2012

▎ 摘  要

We report a unipolar operation in reduced graphene oxide (RGO) field-effect transistors (FETs) via modification of the source/drain (S/D) electrode interfaces with self-assembled monolayers (SAMs) of 5-(4-hydroxyphenyl)-10,15,20-tri-(p-tolyl) zinc(II) porphyrin (Zn(II)TTPOH) molecules. The dipolar Zn(II)TTPOH molecules at the RGO/platinum (Pt) S/D interface results in an increase of the electron injection barrier and a reduction of the hole-injection barrier. Using dipole measurements from Kelvin probe force microscopy and highest occupied molecular orbital lowest unoccupied molecular orbital (HOMO-LUMO) calculations from cyclic voltammetry, the electron and hole injection barriers were calculated to be 2.2 and 0.11 eV, respectively, indicating a higher barrier for electrons, compared to that of holes. A reduced gate modulation in the electron accumulation regime in RGO devices with SAM shows that unipolar RGO FETs can be attained using a low-cost, solution-processable fabrication technique.