Synthesis of large size uniform single-crystalline trilayer graphene on premelting copper

Single-crystalline trilayer graphene (TLG) has attracted intensive interest due to rich optical and electronic properties. However, precise synthesis of large-size uniform single-crystalline TLG with ABA stacking still remains enormous challenge. Herein, an atmospheric pressure chemical vapor deposition (APCVD) process was developed to fabricate the uniform single-crystalline TLG on premelting copper at 1080 °C, which is slightly lower than copper melting temperature. As the results, ∼80 μm uniform single-crystalline TLG with ABA stacking was achieved on a premelting copper layer. Raman mapping and selected area electron diffraction of individual isolated domains reveals they are uniform single-crystalline with ABA stacking. The growth mechanism of the TLG was explored by studying the influence of varied growth temperature, which is subsequently shown that the 2nd and 3rd layer graphene grow simultaneously from external to internal with a twist angle of 20 ± 5°.