Diameter dependent transport properties of gallium nitride nanowire field effect transistors

The authors report transport property measurements of individual GaN nanowire field effect transistors and the correlation of the electron mobilities with the existence of grain boundaries in these nanowires. Room temperature field effect electron mobilities as high as 319cm2V−1s−1 were obtained for the 200nm diameter nanowires. Mobilities calculated from these reliable nanowire field effect transistors indicated that the surface scattering plays a dominant role in smaller diameter nanowires, whereas for intermediate diameter devices transport is dominated by grain boundary scattering. Reduction of the mobility with decreasing diameter of nanowires can be explained using “continuous surface” model.