Laser-Assisted Rapid Fabrication of Large-Scale Graphene Oxide Transparent Conductors

Although graphene films are the main candidate for replacing scarce and brittle metal-oxide transparent conductors, the current challenges on graphene deposition and patterning are severely limiting their commercial application. Here, materials and methods that allow large-scale, efficient, and low-cost fabrication of highly transparent conductors in a few minutes are demonstrated. First, a low-cost graphene oxide (GO) solution through spray coating is deposited, followed by simultaneous reduced graphene oxide reduction and thinning through a low-cost nanosecond fiber laser. It is shown that a 1064 nm master oscillator power amplifier laser enhances the conductivity of GO coated sample by approximate to 60 times, with excellent optical transparency of 90%. The laser parameters are adjusted, and creation of various shades of transparency, conductivity, and a full ablation are demonstrated. This way, complex GO-based circuits can be produced rapidly. Compared to the existing techniques that require chemical vapor deposition, and chemical/thermal reduction, this technique is considerably more accessible, replicable, and can open doors for various applications in optoelectronics, energy storage/harvesting, and sensing. The electrical, chemical, and optical properties of the samples are characterized before and after laser treatment, through optical profilometry, scanning electron microscopy, and (UV, Raman, and energy dispersive X-ray) spectroscopy and applications in transparent conductors, and laser-patterned high-resolution and miniaturized interdigitated sensors are shown.

Automated summary

This study demonstrates a method for large-scale, efficient, and low-cost fabrication of highly transparent conductors. The method involves spray coating a low-cost graphene oxide (GO) solution and then using a nanosecond fiber laser for reduction and thinning. By adjusting the laser parameters, different levels of transparency, conductivity, and full ablation can be achieved.