Laser-induced backward transfer of monolayer graphene

Laser-induced backward transfer (LIBT) has been demonstrated as a viable technique for precise, localised deposition of microscale regions of graphene. Single femtosecond laser pulses, shaped spatially using a digital micromirror device (DMD), were incident on a pre-prepared sample of graphene-coated nickel (the donor substrate) through a transparent glass receiver substrate. Under optimal laser exposure conditions, and in a low-pressure gas environment, circular regions of graphene with approximately 30 µm diameter were successfully transferred from the donor to the receiver substrate as confirmed by optical and electron microscopy and Raman spectroscopy. The hypothesis that rapid thermal expansion of the nickel could drive the transfer process is explored and is shown to be plausible through some simple calculations. This LIBT technique for transfer of this archetypal 2D material has many potential applications in photonic and MEMS device fabrication.