Mask-free and programmable patterning of graphene by ultrafast laser direct writing

- We present a mask-free and programmable patterning of graphene.
- Ultrafast laser can homogeneously reduce graphene oxides into micropatterns.
- Desired graphene micropatterns could be created on flexible substrates.
- Laser exposure duration shows influence on the conductivity of reduced graphene.
- The method holds promise for fabrication and integration of graphene electronics.

Reported here is a mask-free and programmable patterning of graphene by using femtosecond laser direct writing on graphene oxide (GO) films. Take advantage of the ultrahigh instantaneous intensity of the femtosecond laser pulse, and especially its nonlinear interactions with materials, the GO could be efficiently reduced under atmospheric condition at room temperature. Moreover, the designability of femtosecond laser direct writing (FsLDW) technique allow making graphene micropatterns arbitrarily according to the preprogrammed structures, which provides the feasibility for rational design, flexible fabrication and integration of graphene-based micro-devices. Raman spectra show that the reduced and patterned region is very homogeneous, which is confirmed by the almost consistent ID/IG ratio. The novel graphene patterning technique would provide a technical support for the development of graphene-based micro-devices for future electronics.