Abstract
One-dimensional Ⅲ-nitride (AlN, GaN, InN) nanorod structures are well known to have great prospects for fundamental studies and novel technological applications. However, direct determination of the carrier concentrations by Hall effect is not easy if not impossible for nanorod structures. Here, we demonstrate a method which can be applied to study single GaN nanorod p-n junctions grown by plasma-assisted molecular-beam epitaxy (PAMBE) with an in-situ multiple-probe system installed in a field-emission scanning electron microscope (FESEM). We can directly observe the electrostatic potential variation across the depletion region in the reversely biased nanorods, and the electrostatic potential can be determined directly from secondary electron images. In particular, we show that this method can be use for estimating the carrier concentration in single GaN nanorod p-n junctions.