• 文献标题:   Efficient Fabrication of Stable Graphene-Molecule-Graphene Single-Molecule Junctions at Room Temperature
  • 文献类型:   Article
  • 作  者:   SUN HT, JIANG ZL, XIN N, GUO XF, HOU SM, LIAO JH
  • 作者关键词:   singlemolecule junction, graphene electrode, feedbackcontrolled electroburning, covalent coupling, roomtemperature stability
  • 出版物名称:   CHEMPHYSCHEM
  • ISSN:   1439-4235 EI 1439-7641
  • 通讯作者地址:   Peking Univ
  • 被引频次:   2
  • DOI:   10.1002/cphc.201800220
  • 出版年:   2018

▎ 摘  要

We present a robust approach to fabricate stable single-molecule junctions at room temperature using single-layer graphene as nanoelectrodes. Molecular scale nano-gaps in graphene were generated using an optimized fast-speed feedback-controlled electroburning process. This process shortened the time for creating a single nano-gap to be less than one minute while keeping a yield higher than 97%. To precisely control the gap position and minimize the effects of edge defects and the quantum confinement, extra-narrow grooves were pre-patterned in the graphene structures with oxygen plasma etching. Molecular junctions were formed by bridging the nano-gaps with amino-functionalized hexaphenyl molecules by taking advantage of chemical reactions between the amino groups at the two ends of the molecules and the carboxyl groups at the edges of graphene electrodes. Electronic transport measurements and transition voltage spectroscopy analysis verified the formation of single-molecule devices. First-principles quantum transport calculations show that the highest occupied molecular orbital of hexaphenyl is closer to the Fermi level of the graphene electrodes and thus the devices exhibit a hole-type transport characteristics. Some of these molecular devices remained stable up to four weeks, highlighting the potential of graphene nano-electrodes in the fabrication of stable single-molecule devices at room temperature.