Demonstration of distinct semiconducting transport characteristics of monolayer graphene functionalized via plasma activation of substrate surfaces
Journal
Carbon
Journal Volume
93
Pages
353-360
Date Issued
2015
Author(s)
Wang P.-H.
Shih F.-Y.
Chen S.-Y.
Hernandez A.B.
Ho P.-H.
Chang L.-Y.
Chen C.-H.
Chiu H.-C.
Chen C.-W.
Wang W.-H.
Abstract
We report semiconducting behavior of monolayer graphene enabled through plasma activation of substrate surfaces. The graphene devices are fabricated by mechanical exfoliation onto pre-processed SiO2/Si substrates. Contrary to pristine graphene, these graphene samples exhibit a transport gap as well as nonlinear transfer characteristics, a large on/off ratio of 600 at cryogenic temperatures, and an insulating-like temperature dependence. Raman spectroscopic characterization shows evidence of sp3 hybridization of C atoms in the samples of graphene on activated SiO2/Si substrates. We analyze the hopping transport at low temperatures, and weak localization observed from magnetotransport measurements, suggesting a correlation between carrier localization and the sp3-type defects in the functionalized graphene. The present study demonstrates the functionalization of graphene using a novel substrate surface-activation method for future graphene-based applications.
Publisher
Elsevier Ltd
Type
journal article