Engineering electronic properties of graphene by coupling with Si-Rich, two-dimensional Islands

Dong Hyun Lee, Jaeseok Yi, Jung Min Lee, Sang Jun Lee, Yong Joo Doh, Hu Young Jeong, Zonghoon Lee*, Ungyu Paik, John A. Rogers, Won Il Park

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

25 Scopus citations

Abstract

Recent theoretical and experimental studies demonstrated that breaking of the sublattice symmetry in graphene produces an energy gap at the former Dirac point. We describe the synthesis of graphene sheets decorated with ultrathin, Si-rich two-dimensional (2D) islands (i.e., Gr:Si sheets), in which the electronic property of graphene is modulated by coupling with the Si-islands. Analyses based on transmission electron microscopy, atomic force microscopy, and electron and optical spectroscopies confirmed that Si-islands with thicknesses of ∼2 to 4 nm and a lateral size of several tens of nm were bonded to graphene via van der Waals interactions. Field-effect transistors (FETs) based on Gr:Si sheets exhibited enhanced transconductance and maximum-to-minimum current level compared to bare-graphene FETs, and their magnitudes gradually increased with increasing coverage of Si layers on the graphene. The temperature dependent current-voltage measurements of the Gr:Si sheet showed approximately a 2-fold increase in the resistance by decreasing the temperature from 250 to 10 K, which confirmed the opening of the substantial bandgap (∼2.5-3.2 meV) in graphene by coupling with Si islands.

Original languageEnglish (US)
Pages (from-to)301-307
Number of pages7
JournalACS nano
Volume7
Issue number1
DOIs
StatePublished - Jan 22 2013

Keywords

  • bandgap engineering
  • graphene
  • silicon islands
  • sublattice asymmetry
  • van der Waals growth

ASJC Scopus subject areas

  • Materials Science(all)
  • Engineering(all)
  • Physics and Astronomy(all)

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