Temperature-dependent transport properties of an individual GaP nanowire with a Ga ₂O ₃ outer shell

We have studied the temperature dependent transport properties of a GaP nanowire with a Ga ₂O ₃ outer shell. Metal electrodes were contacted to the GaP core region and to an outer oxide layer. Electrical measurements on the core region revealed a pronounced n-type gating effect, whereas insulating behavior was observed in the outer Ga ₂O ₃ layer. The temperature dependence for the current-voltage characteristics of the GaP core region can be explained by using a band bending effect at the interface of the metal electrode and the nanowire. Aperiodic oscillations were also observed in the core channel at low temperatures and could be attributed to a single-electron effect due to multiple quantum dots within the nanowire. Diode-like I-V characteristics were observed between the core and the outer layers and originate from the formation of a GaP/Ga ₂O ₃ heterojunction.