In Situ Growth of Graphene Catalyzed by a Phase‐Change Material at 400 °C for Wafer‐Scale Optoelectronic Device Application

The use of metal foil catalysts in the chemical vapor deposition of graphene films makes graphene transfer an ineluctable part of graphene device fabrication, which greatly limits industrialization. Here, an oxide phase-change material (V2O5) is found to have the same catalytic effect on graphene growth as conventional metals. A uniform large-area graphene film can be obtained on a 10 nm V2O5 film. Density functional theory is used to quantitatively analyze the catalytic effect of V2O5. Due to the high resistance property of V2O5 at room temperature, the obtained graphene can be directly used in devices with V2O5 as an intercalation layer. A wafer-scale graphene-V2O5-Si (GVS) Schottky photodetector array is successfully fabricated. When illuminated by a 792 nm laser, the responsivity of the photodetector can reach 266 mA W-1 at 0 V bias and 420 mA W-1 at 2 V. The transfer-free device fabrication process enables high feasibility for industrialization.