▎ 摘　　要

By combining optical imaging, Raman spectroscopy, kelvin probe force microscopy (KFPM), and photoemission electron microscopy (PEEM), we show that graphene's layer orientation, as well as layer thickness, measurably changes the surface potential (Phi). Detailed mapping of variable-thickness, rotationally-faulted graphene films allows us to correlate Phi with specific morphological features. Using KPFM and PEEM we measure Delta Phi up to 39 mV for layers with different twist angles, while Delta Phi ranges from 36-129 mV for different layer thicknesses. The surface potential between different twist angles or layer thicknesses is measured at the KPFM instrument resolution of