Optimizing the Optical and Electrical Properties of Graphene Ink Thin Films by Laser-annealing

TL;DR

This paper presents a simple laser-annealing method to improve the optical transparency and electrical conductivity of graphene ink thin films, achieving significant enhancements over unannealed films.

Contribution

It introduces a novel laser-annealing process combined with drop casting to produce highly uniform, transparent, and conductive graphene films with improved properties.

Findings

85% transparency at 550 nm

70% reduction in sheet resistance

Fourfold decrease in surface roughness

Abstract

We demonstrate a facile fabrication technique for graphene-based transparent conductive films. Highly flat and uniform graphene films are obtained through the incorporation of an efficient laser annealing technique with one-time drop casting of high-concentration graphene ink. The resulting thin films are uniform and exhibit a transparency of more than 85% at 550 nm and a sheet resistance of about 30 k{\Omega}/sq. These values constitute an increase of 45% in transparency, a reduction of surface roughness by a factor of four and a decrease of 70% in sheet resistance compared to unannealed films.