• 文献标题:   Contactless Spin Switch Sensing by Chemo-Electric Gating of Graphene
  • 文献类型:   Article
  • 作  者:   VAN GEEST EP, SHAKOURI K, FU WY, ROBERT V, TUDOR V, BONNET S, SCHNEIDER GF
  • 作者关键词:   chemoelectric gating, contactless sensing, graphene, molecular material, spin crossover
  • 出版物名称:   ADVANCED MATERIALS
  • ISSN:   0935-9648 EI 1521-4095
  • 通讯作者地址:   Leiden Univ
  • 被引频次:   1
  • DOI:   10.1002/adma.201903575 EA FEB 2020
  • 出版年:   2020

▎ 摘  要

Direct electrical probing of molecular materials is often impaired by their insulating nature. Here, graphene is interfaced with single crystals of a molecular spin crossover complex, [Fe(bapbpy)(NCS)(2)], to electrically detect phase transitions in the molecular crystal through the variation of graphene resistance. Contactless sensing is achieved by separating the crystal from graphene with an insulating polymer spacer. Next to mechanical effects, which influence the conductivity of the graphene sheet but can be minimized by using a thicker spacer, a Dirac point shift in graphene is observed experimentally upon spin crossover. As confirmed by computational modeling, this Dirac point shift is due to the phase-dependent electrostatic potential generated by the crystal inside the graphene sheet. This effect, named as chemo-electric gating, suggests that molecular materials may serve as substrates for designing graphene-based electronic devices. Chemo-electric gating, thus, opens up new possibilities to electrically probe chemical and physical processes in molecular materials in a contactless fashion, from a large distance, which can enhance their use in technological applications, for example, as sensors.