▎ 摘　　要

The interface characteristics of graphene/GaN samples using X-ray photoelectron spectroscopy (XPS) measurements are investigated. XPS makes it possible to extract a reliable barrier-height value. For graphene/n-type GaN (graphene/p-type GaN) samples, the Schottky barrier height is 0.85 (2.50) eV. To determine the Fermi-level pinning/unpinning at the graphene/GaN interfaces, an analysis is conducted according to the Schottky-Mott limit. It is shown that the Fermi energy level is unpinned and the barrier-height value is dependent on the work function of graphene. Investigation of graphene/GaN interfaces is important, and providing the other technique for surface potential control is possible.