Workfunction variation across surface of an H-terminated diamond film measured using Kelvin probe force microscopy

► Kelvin probe force microscopy (KPM) performed on H-terminated diamond surface in ultra-high vacuum. ► Local variations in contact potential show work function variation up to 350 mV. ► Variations are observed even for structures of the same crystal orientation. ► The results show the Chemical vapour deposition (CVD) diamond work function is strongly affected by morphology.