▎ 摘　　要

The remarkable properties of graphene/SiC heterostructures have demonstrated promise for use in future power electronics; however, the substrate-induced strain is detrimental to the optimal yield. Epitaxial graphene (EG) grown on nominally low miscut angled (0.05 degrees off-axis) SiC (0001) intensely suffers from substrate-induced biaxial strain via a buffer layer. Buffer layer-free quasifreestanding graphene (QFSG) grown on high miscut angled (8 degrees off-axis) vicinal SiC using the one-pot synthesis, as compared to EG/SiC (0001), exhibits contrasting Raman 2D-peak features. In this study, the substrate-induced strain exerted on graphene grown on both nominal and vicinal SiC was quantitatively investigated using Raman 2D mapping, and the unstrained feature of QFSG was demonstrated on vicinal SiC. Furthermore, metal-graphene-metal devices were fabricated and photocurrent enhancements of 430-and 150-fold were observed in QFSG/vicinal SiC devices, as compared to EG/SiC (0001), with and without gold nanoparticles, respectively. The significantly increased conductivity and photoresponse of the QFSG/vicinal SiC heterostructure, as compared to that of EG/SiC (0001), will increase the potential of gFOraphene/SiC heterostructures in practical SiC microelectronics applications.