Abstract Nano-electronic devices incorporating Van der Waals electrical contact, particularly on two-dimensional semiconductor, offer exceptional electrical performance. However, the fabrication of Van der Waals electrical contact is still a challenge. Here, layered reduced graphene oxide (rGO) flakes are employed as buffer to construct the Van der Waals electrical contact in monolayer molybdenum disulfide (MoS2) transistors, and screen the Fermi-level pinning effect. The results show that the work function of monolayer MoS2 would increase by 0.12 eV and its electron concentration would decrease by 0.74 × 1012 cm−2, demonstrating the p-type doping role of rGO flakes. To quantitatively reveal the role of rGO buffer layer during the electrode fabrication, the MoS2 transistors w/o rGO buffer layer were fabricated on single monocrystalline MoS2 domain. Though comparatively studying the electrical properties at room/low temperature, it has been demonstrated the rGO buffer layer would contribute to forming van der Waals contacts and lead the dramatically decrease of Schottky barrier resulting in about ten times device mobility enhancement in MoS2 transistor.

中文翻译：

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通过范德华接触到单层二硫化钼来筛选费米能级钉扎效应

摘要 包含范德华电接触的纳米电子器件，特别是在二维半导体上，提供了卓越的电气性能。然而，范德华电接触的制造仍然是一个挑战。在这里，层状还原氧化石墨烯 (rGO) 薄片被用作缓冲，以在单层二硫化钼 (MoS2) 晶体管中构建范德华电接触，并屏蔽费米能级钉扎效应。结果表明，单层 MoS2 的功函数将增加 0.12 eV，其电子浓度将减少 0.74 × 1012 cm-2，证明了 rGO 薄片的 p 型掺杂作用。为了定量揭示 rGO 缓冲层在电极制造过程中的作用，在单晶 MoS2 域上制造了没有 rGO 缓冲层的 MoS2 晶体管。