The mechanism of direct laser writing of graphene features into graphene oxide films involves photoreduction and thermally assisted structural rearrangement

Photoreduction of graphene oxide (GO) to reduced graphene oxide (rGO) under ambient conditions was evaluated for three laser processing approaches: 800 nm fs pulses, 248 nm ns pulses, and 788 nm continuous wave (CW) illumination. Resultant features were compared using Raman, XPS, optical profilometry and SEM. The most effective approach for photoreduction and graphenization with minimal defects was nanosecond processing (0.12 J cm−2; 40 pulses...