• 文献标题:   pH Sensitivity of Edge-Gated Graphene Field-Effect Devices with Covalent Edge Functionalization
  • 文献类型:   Article, Early Access
  • 作  者:   NEUBERT TJ, KRIEG J, YADAV A, BALASUBRAMANIAN K
  • 作者关键词:   graphene nanoribbon, graphene edge, sensing, covalent modification, 2d material
  • 出版物名称:   ACS APPLIED ELECTRONIC MATERIALS
  • ISSN:  
  • 通讯作者地址:  
  • 被引频次:   1
  • DOI:   10.1021/acsaelm.2c00880 EA SEP 2022
  • 出版年:   2022

▎ 摘  要

We introduce here a strategy for a field-effect device, termed graphene edge field-effect transistor (GrEdge-FET), where a micron-wide graphene monolayer is gated exclusively through its edge in an aqueous environment. This is achieved by passivating the basal plane selectively using photolithography. We observe a field-effect behavior in buffer solutions with an ON/OFF ratio of nearly 10 in a small gate-voltage range (+/- 0.5 V) without any need for complex nanofabrication or specialized electrolytes. We attribute this effect to the electrical double layer capacitance at the edge-electrolyte interface, which efficiently gates the entire graphene sheet although it acts only at the edge. We demonstrate that GrEdge-FET devices find applications as pH sensors. Through diazonium electrochemistry, the edges are functionalized persistently with substituted phenyl moieties, which renders the devices with a higher pH sensitivity than classical graphene FETs. Moreover, since only the edge is modified, the favorable field-effect behavior is preserved, despite the covalent nature of the attachment of the functional groups.