Self-screened high performance multi-layer MoS₂ transistor formed by using a bottom graphene electrode

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Carrier transport in multi-layer MoS2 is hindered by contact (R(c)) and interlayer (R(int)) resistance.
• Device performance degrades with increasing MoS2 thickness due to accumulated R(int) and R(c).

Purpose of the Study:

• To investigate carrier transport in multi-layer MoS2 FETs.
• To mitigate performance degradation caused by R(int) and R(c) using novel contact strategies.

Main Methods:

• Fabrication of multi-layer MoS2 field-effect transistors (FETs).
• Utilized bottom graphene contacts to interface with MoS2.
• Characterized device performance, including drain current (I(d)) modulation and carrier mobility.

Main Results:

• Achieved non-degraded I(d) modulation with increasing MoS2 flake thickness.
• Demonstrated significantly reduced R(c) due to a negligible Schottky barrier at the graphene/MoS2 interface.
• Observed approximately 2x enhanced carrier mobility attributed to the self-screened channel effect.

Conclusions:

• Bottom graphene contacts effectively overcome R(int) and R(c) limitations in multi-layer MoS2 FETs.
• This approach enables investigation of intrinsic carrier transport properties.
• Graphene-contacted MoS2 FETs exhibit superior carrier mobility, paving the way for advanced electronic devices.