Liquid Cu-Zn catalyzed growth of graphene single-crystals

The chemical vapor deposition (CVD) method has been widely used for growing large-scale graphene films on a metal substrate. Due to the drawbacks of single metal substrates, alloy substrates have gradually attracted attention owing to the exceptional characteristics derived from different metals, making them an enticing choice. In this study, a novel liquid Cu-Zn alloy catalyst was introduced for the first time for the preparation of millimeter-sized, single-crystal monolayer graphene using the CVD approach. Notably, the graphene synthesized on the liquid Cu-Zn alloy catalyst exhibited distinct advantages in terms of its larger size and lower nucleation density compared to graphene grown on the conventional liquid Cu catalyst. The uniformity of large-sized graphene's electrical properties was confirmed by 2D resistivity measurements and tests on field effect transistor (FET) devices. This work was put forward to inspire the novel design of alloy catalysts and the synthesis of graphene films bearing desirable properties. The controllable synthesis of millimeter-sized single-crystal monolayer graphene on a liquid Cu-Zn alloy by suppressing nucleation is reported.