Synthesis of Laser-Induced Graphene Using a 450 nm Diode Laser

The results of experiments on the synthesis of laser-induced graphene (LIG) on the surface of polyimide film via pyrolysis induced by radiation from commercial pulsed diode lasers with a wavelength of 450 nm, operating in either line-by-line or raster regime, are presented. To better understand the unique aspects of LIG synthesis using diode lasers, an investigation was conducted into the operations of three distinct models of laser heads. It is demonstrated that the surface morphology, thickness, and hydrophilicity of LIG film structures synthesized in either a line-by-line or raster regime differ significantly from one another. The thickness of LIG films synthesized in the raster regime is not uniform over the area, with a variation reaching ±60% of the average value. In the line-by-line regime, LIG films about 130 μm thick have been produced with a scatter of ±20%. Regardless of the incident fluence, the LIG synthesized in the raster regime is hydrophobic. In the line-by-line regime, both hydrophilic and hydrophobic LIG films can be produced depending on fluence.