Recoverable Patterning of Macro-Assembled Graphene Nanofilms

Patterning is a crucial fabrication step for successfully applying two-dimensional materials in electronic and optoelectronic devices. It can realize miniaturization and help explore new physical phenomena of 2D materials. However, the manufacturing process inevitably introduces defects, which require harsh conditions to recover. Here, we propose a sputtering-lithography-annealing (SLA) strategy for patterning graphene nanofilm with pattern sizes ranging from microns to 100 nm scale without lattice damage. The sputtered masking agents can introduce easily repairable defects into graphene films. Especially, defects introduced by aluminum can be removed entirely. To confirm the validity of the SLA strategy, we prepared macro-assembled graphene nanofilms (nMAG)/Ge and nMAG/Si heterojunction arrays for infrared detection. The patterned detectors present a responsivity of 0.09 A/W at
$2 \mu \text{m}$
(nMAG/Ge) and 26.4 mA/W at 1550 nm (nMAG/Si) with a high array homogeneity, similar to the devices without patterning. This strategy lays the foundation for further exploration of new superstructures of nMAG and can be extended to other 2D materials.