• 文献标题:   Lowering the Schottky Barrier Height by Graphene/Ag Electrodes for High-Mobility MoS2 Field-Effect Transistors
  • 文献类型:   Article
  • 作  者:   CHEE SS, SEO D, KIM H, JANG H, LEE S, MOON SP, LEE KH, KIM SW, CHOI H, HAM MH
  • 作者关键词:   ag, fieldeffect transistor, graphene, molybdenum disulfide, transition metal dichalcogenide
  • 出版物名称:   ADVANCED MATERIALS
  • ISSN:   0935-9648 EI 1521-4095
  • 通讯作者地址:   GIST
  • 被引频次:   44
  • DOI:   10.1002/adma.201804422
  • 出版年:   2019

▎ 摘  要

2D transition metal dichalcogenides (TMDCs) have emerged as promising candidates for post-silicon nanoelectronics owing to their unique and outstanding semiconducting properties. However, contact engineering for these materials to create high-performance devices while adapting for large-area fabrication is still in its nascent stages. In this study, graphene/Ag contacts are introduced into MoS2 devices, for which a graphene film synthesized by chemical vapor deposition (CVD) is inserted between a CVD-grown MoS2 film and a Ag electrode as an interfacial layer. The MoS2 field-effect transistors with graphene/Ag contacts show improved electrical and photoelectrical properties, achieving a field-effect mobility of 35 cm(2) V-1 s(-1), an on/off current ratio of 4 x 10(8), and a photoresponsivity of 2160 A W-1, compared to those of devices with conventional Ti/Au contacts. These improvements are attributed to the low work function of Ag and the tunability of graphene Fermi level; the n-doping of Ag in graphene decreases its Fermi level, thereby reducing the Schottky barrier height and contact resistance between the MoS2 and electrodes. This demonstration of contact interface engineering with CVD-grown MoS2 and graphene is a key step toward the practical application of atomically thin TMDC-based devices with low-resistance contacts for high-performance large-area electronics and optoelectronics.