We report on investigation of the AC dielectrophoresis aligned assembly deposition (DAAD) of gallium nitride nanowires (GaN NWs) with both the variation of the electric field and the frequency. Our DAAD methods were used to align and manipulate GaN nanowires as well as to extract the electrical properties of semiconducting nanowires. We observed that the ability of the alignment strongly depends on the magnitude of the AC electric field and frequencies. For the higher AC peak-to-peak electric fields (up to 20 Vp-p), the GaN nanowires have a better alignment across the patterned Ti / Au electrodes with a high yield rate of ~ 90% over the entire arrays (in our case, 20 arrays) in the chip at the 20 kHz. From the transport measurements of our AC aligned GaN nanowires using conventional three-probe schemes in field-effect transistor structures, we found that the conductance of the GaN NWs increased for gating voltage greater than zero and decreased for gating voltage less than zero, indicating these GaN nanowires have n-type dopants.
