Abstract:
Film samples of laser-induced graphene (LIG) were synthesized on the surface of polyimide film through line-by-line scanning with a focused beam of a continuous-wave carbon dioxide laser. The structure and chemical composition of the near-surface layer of the synthesized material were investigated as a function of the scanning speed $v$ of the laser beam. It was found that a decrease in $v$ from 400 to 10 mm/s leads to an increase in nitrogen concentration by more than 11 times. At an optimal laser power of 0.55 W and a speed of $v$ = 10 mm/s, the nitrogen concentration reaches 5.7 at.%. It has been demonstrated that the increase in nitrogen concentration with a decrease in v occurs due to the pyridine and pyrrole configurations of nitrogen in the nanocrystalline structure of graphite, which is accompanied by a significant reduction in the surface resistance of LIG. The obtained results correlate with the previously established multiple increase in the electrochemical capacitance of LIG with a decrease in $v$.
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