Controlling Thermoelectric Properties of Laser-Induced Graphene on Polyimide

Area of Science:

• Materials Science
• Energy Conversion
• Nanotechnology

Background:

• Graphene-based materials are promising for wearable thermoelectric generators due to cost and tunable properties.
• High thermal conductivity of graphene presents a challenge for thermoelectric applications.
• Laser-induced graphene (LIG) offers a porous structure, low cost, and scalability.

Purpose of the Study:

• Investigate thermoelectric properties of LIG on polyimide.
• Analyze the dependence of these properties on structural modifications of LIG.
• Determine the effect of laser scribing power on LIG's thermoelectric performance.

Main Methods:

• Fabrication of LIG on polyimide via laser scribing.
• Characterization of LIG structure (flake size, graphitization) at varying laser powers.
• Measurement of electrical conductivity and Seebeck coefficient.
• Assessment of thermal conductivity and thermoelectric figure of merit (ZT).

Main Results:

• Increasing laser power enhanced graphitization and electrical conductivity.
• LIG exhibited p-type semiconducting behavior with a positive Seebeck coefficient.
• Seebeck coefficient and electrical conductivity increased simultaneously with laser power.
• Low thermal conductivity (0.6-0.85 W/m·K) was observed due to the porous structure.
• Thermoelectric figure of merit (ZT) improved nearly tenfold with increased laser power.

Conclusions:

• Laser power is a critical parameter for tuning LIG's thermoelectric properties.
• LIG demonstrates significant potential for high-performance wearable thermoelectric generators.
• The tunable nature of LIG makes it highly adaptable for various energy harvesting applications.