To improve the laser-induced graphene formation on polyimide(PI)films and the edge quality of the laser-irradiated area

a CO

2

laser with a wavelength of 10.64μm and a ultraviolet solid-state laser with a wavelength of 266nm

experiments on infrared laser-induced carbonization

ultraviolet laser-induced carbonization are conducted

and sequential ultraviolet-then-infrared laser-induced carbonization on the PI film surface.The carbonized products are characterized using a scanning electron microscope(SEM)

Raman spectrometer

and atomic force microscope(AFM).The experimental results indicate that the inf

rared laser induces the formation of graphene on PI films

but the edge quality in the irradiated area is relatively poor;the ultraviolet laser induces graphite-like materials in the form of "small protrusions" with heights of 2~6μm on the PI films

and the edge quality in the irradiated area is relatively good;and the ultraviolet irradiation followed by infrared irradiation method

induces the formation of graphene with improved edge quality in the irradiated area.The above research serves as a reference for directly generating graphene required for flexible sensors on PI films using lasers.