Electroless Nickel Deposition: An Alternative for Graphene Contacting

Area of Science:

• Materials Science
• Nanotechnology
• Electrical Engineering

Background:

• Graphene's unique electronic properties make it ideal for next-generation devices.
• Achieving low-resistance electrical contacts is crucial for graphene device performance.
• Current methods for graphene metallization can be complex and costly.

Purpose of the Study:

• To investigate electroless nickel deposition as a viable method for forming ohmic contacts on single-layer graphene.
• To optimize the nickel deposition process for improved contact resistance and film properties.
• To assess the potential for low-cost, large-scale integration of graphene in electronic applications.

Main Methods:

• Utilized a statistical model to optimize nickel bath parameters (pH, temperature) for enhanced metal purity, surface roughness, and film coverage.
• Employed photolithography for patterning metalized graphene layers.
• Deposited nickel contacts at temperatures as low as 60 °C.

Main Results:

• Achieved a contact resistance of 215 ± 23 Ω over a 200 μm × 200 μm area on single-layer graphene.
• Improved contact resistance to 107 ± 9 Ω after rapid annealing.
• Demonstrated successful low-temperature deposition and patterning of nickel contacts.

Conclusions:

• Electroless nickel deposition is a promising technique for creating low-resistance ohmic contacts on graphene.
• The optimized process enables cost-effective and scalable integration of graphene into electronic devices.
• This method supports the development of flexible sensors and printed electronics utilizing graphene.