Electromechanical Characterization of Single GaN Nanobelt Probed with Conductive Atomic Force Microscope

The electromechanical characterization of the field effect transistor based on a single GaN nanobelt was performed under different loading forces by using a conductive atomic force microscope (C-AFM), and the effective Schottky barrier height (SBH) and ideality factor are simulated by the thermionic emission model. From 2-D current image, the high value of the current always appears on the nanobelt edge with the increase of the loading force less than 15 nN. The localized (I–V) characteristic reveals a typical rectifying property, and the current significantly increases with the loading force at the range of 10–190 nN. The ideality factor is simulated as 9.8 within the scope of GaN nano-Schottky diode unity (6.5–18), therefore the thermionic emission current is dominant in the electrical transport of the GaN-tip Schottky junction. The SBH is changed through the piezoelectric effect induced by the loading force, and it is attributed to the enhanced current. Furthermore, a single GaN nanobelt has a high mechanical-induced current ratio that could be made use of in a nanoelectromechanical switch.