• 文献标题:   On-Surface Synthesis of Variable Bandgap Nanoporous Graphene
  • 文献类型:   Article
  • 作  者:   WANG DG, LU XF, ARRAMEL, YANG M, WU JS, WEE ATS
  • 作者关键词:   bandgap modulation, densityfunctional theory calculation, lowtemperature scanning tunneling microscopy, noncontact atomic force microscopy, nanoporous graphene, onsurface synthesi
  • 出版物名称:   SMALL
  • ISSN:   1613-6810 EI 1613-6829
  • 通讯作者地址:  
  • 被引频次:   2
  • DOI:   10.1002/smll.202102246 EA SEP 2021
  • 出版年:   2021

▎ 摘  要

Tuning the bandgap of nanoporous graphene is desirable for applications such as the charge transport layer in organic-hybrid devices. The holy grail in the field is the ability to synthesize 2D nanoporous graphene with variable pore sizes, and hence tunable band gaps. Herein, the on-surface synthesis of nanoporous graphene with variable bandgaps is demonstrated. Two types of nanoporous graphene are synthesized via hierarchical C-C coupling, and are verified by low-temperature scanning tunneling microscopy and non-contact atomic force microscopy. Nanoporous graphene-1 is non-planar, and nanoporous graphene-2 is a single-atom thick planar sheet. Scanning tunneling spectroscopy measurements reveal that nanoporous graphene-2 has a bandgap of 3.8 eV, while nanoporous graphene-1 has a larger bandgap of 5.0 eV. Corroborated by first-principles calculations, it is proposed that the large bandgap opening is governed by the confinement of pi-electrons induced by pore generation and the non-planar structure. The finding shows that by introducing nanopores or a twisted structure, semi metallic graphene is converted into semiconducting nanoporous graphene-2 or insulating wide-bandgap nanoporous graphene-1.