Direct Determination of Field Emission across the Heterojunctions in a ZnO/Graphene Thin-Film Barristor

详细信息    查看全文

• 作者：Edmund M. Mills ; Bok Ki Min ; Seong K. Kim ; Seong Jun Kim ; Min-A Kang ; Wooseok Song ; Sung Myung ; Jongsun Lim ; Ki-Seok An ; Jongwan Jung ; Sangtae Kim
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2015
• 出版时间：August 26, 2015
• 年：2015
• 卷：7
• 期：33
• 页码：18300-18305
• 全文大小：311K
• ISSN：1944-8252

文摘

Graphene barristors are a novel type of electronic switching device with excellent performance, which surpass the low on鈥搊ff ratios that limit the operation of conventional graphene transistors. In barristors, a gate bias is used to vary graphene鈥檚 Fermi level, which in turn controls the height and resistance of a Schottky barrier at a graphene/semiconductor heterojunction. Here we demonstrate that the switching characteristic of a thin-film ZnO/graphene device with simple geometry results from tunneling current across the Schottky barriers formed at the ZnO/graphene heterojunctions. Direct characterization of the current鈥搗oltage鈭抰emperature relationship of the heterojunctions by ac-impedance spectroscopy reveals that this relationship is controlled predominantly by field emission, unlike most graphene barristors in which thermionic emission is observed. This governing mechanism makes the device unique among graphene barristors, while also having the advantages of simple fabrication and outstanding performance.