Demonstration of distinct semiconducting transport characteristics of monolayer graphene functionalized via plasma activation of substrate surfaces. (November 2015)

• Record Type: Journal Article
• Authors: Wang, Po-Hsiang; Shih, Fu-Yu; Chen, Shao-Yu; Hernandez, Alvin B.; Ho, Po-Hsun; Chang, Lo-Yueh; Chen, Chia-Hao; Chiu, Hsiang-Chih; Chen, Chun-Wei; Wang, Wei-Hua
• Is Part Of: Carbon. Volume 93(2015)
• Page Start: 353
• Page End: 360
• Publication Date: 2015-11
• Subjects: Carbon -- Periodicals; Carbone -- Périodiques; Koolstof; Toepassingen; Electronic journals; 546.681
• DOI: 10.1016/j.carbon.2015.05.060
• Languages: English
• ISSNs: 0008-6223

Abstract

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 sp 3 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 sp 3 -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.