Fabrication and optimization of transparent conductive films using laser annealing and picosecond laser patterning

Abstract

In this article, we propose a systematic method of optimizing the properties of transparent conductive films that possess high electrical conductivity and low optical transparency, by using laser patterning and doping. Prediction maps were constructed, which show the effects of patterning and doping for all possible combinations of initial film conditions (in terms of sheet resistance and transparency) and the degrees of patterning. Using these maps, the properties of transparent conductive films can be easily optimized. We first fabricated graphene-based transparent conductive films on fused silica glass by laser annealing of diamond-like carbon films, and then picosecond laser patterning and doping were successively conducted employing the processing conditions suggested by the maps. For patterning, two types of patterns, circular and square, were considered and prediction maps were separately constructed for both patterns. In this study, a film originally having a sheet resistance of 578 Ω/sq and a transparency of 25% was transformed to a 2823 Ω/sq and 80.6% film when 73% of the film was removed using square patterns and doped by nitric acid. Experimental data agreed well with predicted values.