title: Low-Resistance 2D/2D Ohmic Contacts: A Universal Approach to High-Performance WSe2, MoS2, and MoSe2 Transistors.
abstract: 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 WSe2 field-effect transistors (FETs) with 2D/2D contacts exhibit low contact resistances of ∼0.3 kΩ μm, high on/off ratios up to >10(9), and high drive currents exceeding 320 μA μm(-1). These favorable characteristics are combined with a two-terminal field-effect hole mobility μFE ≈ 2 × 10(2) cm(2) V(-1) s(-1) at room temperature, which increases to >2 × 10(3) cm(2) V(-1) s(-1) at cryogenic temperatures. We observe a similar performance also in MoS2 and MoSe2 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.
authors: Physics and Astronomy Department, Wayne State University , Detroit, Michigan 48201, United States.
authors: Hsun-Jen
authors: HJ
authors: Chuang
authors: Physics and Astronomy Department, Wayne State University , Detroit, Michigan 48201, United States.
authors: Bhim
authors: B
authors: Chamlagain
authors: Department of Materials Science and Engineering, The University of Tennessee , Knoxville, Tennessee 37996, United States.
authors: Michael
authors: M
authors: Koehler
authors: Physics and Astronomy Department, Wayne State University , Detroit, Michigan 48201, United States.
authors: Meeghage Madusanka
authors: MM
authors: Perera
authors: Department of Materials Science and Engineering, The University of Tennessee , Knoxville, Tennessee 37996, United States.|Materials Science and Technology Division, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States.
authors: Jiaqiang
authors: J
authors: Yan
authors: Department of Materials Science and Engineering, The University of Tennessee , Knoxville, Tennessee 37996, United States.|Materials Science and Technology Division, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States.
authors: David
authors: D
authors: Mandrus
authors: Physics and Astronomy Department, Michigan State University , East Lansing, Michigan 48824, United States.
authors: David
authors: D
authors: Tománek
authors: Physics and Astronomy Department, Wayne State University , Detroit, Michigan 48201, United States.
authors: Zhixian
authors: Z
authors: Zhou
keywords: MoS2; MoSe2; WSe2; field-effect transistor; ohmic contact; two-dimensional