Conductive AFM study of the electronic properties of individual epitaxial GaN nanowires

In this work, we use conductive atomic force microscopy (CAFM) to study the impact of substrate surface preparation and buffer layer composition on the electrical transport properties of GaN nanowires (NWs). I-V curves of single NWs from seven differently prepared samples were obtained. The tip of atomic force microscope (AFM) was used as a top conductive electrode to create stable electric contact to NW free upper grain, while the bottom contact was established between the highly doped Si substrate and a grounded sample holder of the AFM device. Single NW I-V curves were compared to those of NW arrays. The difference between them was discussed.