Rapid fabrication of transparent conductive films with controllable sheet resistance on glass substrates by laser annealing of diamond-like carbon films

Abstract

We report a laser-based method for directly fabricating large-area, transparent conductive films with customizable electrical resistance on glass. In this method, a diamond-like carbon (DLC) film is deposited first on a glass substrate by pulsed laser deposition, which is then annealed in a helium shielding environment by a 2 kW continuous-wave fiber laser with a wavelength of 1070 nm, which is transparent to glass but is absorbed by DLC to transform the amorphous carbons to graphene. When a 510 nm thick film was annealed at a scanning speed of 1 m/s by a 200 μm top-hat laser beam, the sp3 fraction was decreased from 43.1% to 8.1% after the annealing process, and the transformed film showed a transparency of ∼80% (at 550 nm) and a sheet resistance of ∼2050 Ω/sq. We also showed that sheet resistance and transparency can be controlled by changing processing parameters. To show the scalability of the method, a 15 mm wide line beam was used to produce a 15 mm × 15 mm film. This method is simple, fully scalable, transfer-free and catalyst-free, and we believe that the fabricated films can have many applications with further research, such as transparent heating films, electromagnetic shielding films, and transparent electrodes.