In-plane gate graphene transistor with epitaxially grown molybdenum disulfide passivation layers

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Graphene exhibits excellent electronic properties but can suffer from environmental instability.
• Molybdenum disulfide (MoS2) is a 2D material with potential as a protective layer.
• Heterostructures offer synergistic properties for advanced electronic devices.

Purpose of the Study:

• To investigate the use of MoS2 as a passivation layer in graphene-based transistors.
• To fabricate and characterize in-plane gate transistors utilizing a MoS2/graphene heterostructure.
• To evaluate the impact of MoS2 passivation on device performance and stability.

Main Methods:

• Fabrication of in-plane gate transistors with a MoS2/graphene heterostructure.
• Electrical characterization of devices with and without MoS2 passivation.
• Comparison of device performance metrics, including hysteresis, contact resistance, drain current, and field-effect mobility.

Main Results:

• The MoS2 layer effectively passivates the graphene channel, leading to weak device hysteresis.
• Devices with direct electrode/graphene contact exhibit reduced contact resistance and increased drain current.
• Enhanced field-effect mobility was observed, exceeding Hall measurement values, indicating higher carrier concentration.

Conclusions:

• MoS2 serves as an effective passivation layer for graphene channels in transistors.
• Direct electrode contact significantly improves the performance of MoS2/graphene transistors.
• The enhanced mobility suggests improved carrier transport and conductivity in the passivated graphene channel.