Single-step fiber laser reduction and patterning of graphene oxide films for ceramic-based heaters

Abstract

A single-step reduction and patterning technique that involves high-pulse nanosecond fiber laser irradiation was used to reduce graphene oxide films (GOFs) for use in ceramic-based heaters. Laser reduction of GOFs was performed at a laser power, scan speed, pulse repetition frequency, and laser scan pitch of 2.2–4.1 W, 150–500 mm/s, 750 kHz, and 10 μm, respectively. The optimal intensity ratios of the D to G band (RD/G) and the 2D to G band (R2D/G) of reduced GOFs (RGOFs), obtained from Raman spectra, were 0.251 and 0.587, respectively. Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy analyses revealed that oxygen-containing functional groups in RGOFs coated onto ceramic substrates were removed by increasing the average laser power and decreasing the laser scanning speed. Moreover, the typical RGOFs exhibited a lowest sheet resistance of 22.75 ± 2.75 Ω/□, which was achieved with an average laser power and scan speed of 3.35 W and 300 mm/s, respectively. The highest temperature of the typical laser-patterned RGOFs was approximately 123.3 °C, which occurred when the RGOFs were produced using a laser power, scan speed, and applied direct current voltage of 3.27 W, 200 mm/s, and 10 V, respectively.