Ideality factor and barrier height for a GaN nanomembrane electrically contacted with a tungsten nano-tip in a TEM

In the present article, the electrical characteristics of a freestanding gallium nitride nanomembrane in contact with a tungsten nanoprobe are evaluated using scanning tunneling microscopy in an aberration-corrected transmission electron microscope without any lithographic patterning. We report here barrier height (ΦB=0.33±0.05eV and ideality factor (ηW/GaN−NM=1.620±0.07) parameters as extracted from I–V characteristic curve. Our experimental findings, combined with analytical calculations, show that the use of nanosized edge contacts results in a reduced barrier height, which is very promising for achieving a high ‘on’ current, large photoresponse, and high-frequency operation in FET devices.