Resistivity of Rotated Graphite-Graphene Contacts

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Achieving robust electrical contact to two-dimensional (2D) materials like graphene is essential for practical electronic applications.
• Conventional metallic contacts to graphene often exhibit high contact resistivity, limiting device performance.

Purpose of the Study:

• To investigate the use of single-crystal graphite as a bulk contact material for graphene.
• To explore methods for reducing contact resistivity in graphene-based devices.

Main Methods:

• Utilized single-crystal graphite as a bulk contact material instead of traditional metals.
• Investigated the effect of relative crystal orientation between graphite and graphene on contact resistivity.
• Analyzed the periodicity of contact resistivity with respect to crystal orientation.

Main Results:

• Graphite contacts demonstrated significantly longer transfer lengths compared to metallic contacts.
• Achieved contact resistivity as low as 6.6 Ω μm(2) by optimizing graphite-graphene crystal orientation.
• Observed a 60° periodicity in contact resistivity, linked to crystal symmetry, with notable decreases at specific angles (22°, 39°).

Conclusions:

• Single-crystal graphite offers a superior alternative to metallic contacts for 2D materials.
• Tuning the relative crystal orientation is a key factor in minimizing contact resistivity.
• The findings provide a pathway for enhanced electrical performance in graphene-based electronics.