Low-Resistance 2D/2D Ohmic Contacts: A Universal Approach to High-Performance WSe2, MoS2, and MoSe2 Transistors

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• 作者：Hsun-Jen Chuang ; Bhim Chamlagain ; Michael Koehler ; Meeghage Madusanka Perera ; Jiaqiang Yan ; David Mandrus ; David Tománek ; Zhixian Zhou
• 刊名：Nano Letters
• 出版年：2016
• 出版时间：March 9, 2016
• 年：2016
• 卷：16
• 期：3
• 页码：1896-1902
• 全文大小：506K
• ISSN：1530-6992

文摘

We report a new strategy for fabricating 2D/2D low-resistance ohmic contacts for a variety of transition metal dichalcogenides (TMDs) using van der Waals assembly of substitutionally doped TMDs as drain/source contacts and TMDs with no intentional doping as channel materials. We demonstrate that few-layer WSe<sub>2sub> field-effect transistors (FETs) with 2D/2D contacts exhibit low contact resistances of ∼0.3 kΩ μm, high on/off ratios up to >10<sup>9sup>, and high drive currents exceeding 320 μA μm<sup>–1sup>. These favorable characteristics are combined with a two-terminal field-effect hole mobility μ<sub>FEsub> ≈ 2 × 10<sup>2sup> cm<sup>2sup> V<sup>–1sup> s<sup>–1sup> at room temperature, which increases to >2 × 10<sup>3sup> cm<sup>2sup> V<sup>–1sup> s<sup>–1sup> at cryogenic temperatures. We observe a similar performance also in MoS<sub>2sub> and MoSe<sub>2sub> FETs with 2D/2D drain and source contacts. The 2D/2D low-resistance ohmic contacts presented here represent a new device paradigm that overcomes a significant bottleneck in the performance of TMDs and a wide variety of other 2D materials as the channel materials in postsilicon electronics.