Synchronous and Unidirectional Epitaxy of Layer-Controlled Graphene on Oxidized Single-Crystal Copper Wafers With Tunable Stacking Order

The deterministic synthesis of wafer-scale two-dimensional (2D) materials with programmable layer number, crystallographic orientation, and stacking order is essential for unlocking their layer-dependent quantum properties and enabling scalable device integration. Here, we demonstrate a synchronous and unidirectional epitaxy strategy for chemical vapor deposition growth of layer-controlled graphene on atomically flat oxidized single-crystal Cu wafers. Using a Cu(111)-Cu₂O(111) heterogeneous catalytic substrate, we achieved 2-inch single-crystalline graphene films with precisely tunable layer numbers (2 to 5). By engineering the atomic steps of high-index Cu surfaces, we created deterministic spatial patterning of alternating Bernal and rhombohedral stacking in trilayer graphene, as confirmed by near-field nano-optics and angle-resolved photoemission spectroscopy. The resulting wafer-scale films exhibit exceptional thickness uniformity, high crystallinity, and an ultra-flat surface. This work provides a unified growth framework that concurrently resolves the intertwined challenges of layer control, wafer-scale single crystallinity, and stacking order modulation, laying a material foundation for advanced device studies and potential applications.