Electrical transport properties of a nanorod GaN p-n homojunction grown by molecular-beam epitaxy

We investigated the electrical properties of a GaN nanorod p-n junction diode patterned on a SiO2 substrate using e-beam lithography. The electron transport mechanisms were characterized by temperature-dependence and current-voltage measurements. At a low temperature, the current-voltage curves showed that the current slowly increased with a given voltage for the forward bias and hardly changed for the reverse bias, indicating the tunneling current dominates through the deep trap barrier. At a high temperature, however, the current-voltage curves exhibited strong temperature dependence suggesting that thermionic emission with an activation energy of 19.1meV over a barrier dominated.