Low-Resistance 2D/2D Ohmic Contacts: A Universal Approach to   High-Performance WSe2, MoS2, and MoSe2 Transistors
  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 k ohm.um, high on/off ratios up to > 109, and high drive currents exceeding 320 uA um-1. These favorable characteristics are combined with a two-terminal field-effect hole mobility ~ 2x102 cm2 V-1 s-1 at room temperature, which increases to >2x103 cm2 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 post-silicon electronics. 
Hsun-Jen Chuang, Bhim Chamlagain, Michael Koehler, Meeghage Madusanka   Perera, Jiaqiang Yan, David Mandrus, David Tomanek, ...
cond-mat.mes-hall cond-mat.mtrl-sci