Electrical characterization of ensemble of GaN nanowires grown by the molecular beam epitaxy technique

Abstract

High quality Schottky contacts are formed on GaN nanowires (NWs) structures grown by the molecular beam epitaxy technique on Si(111) substrate. The current-voltage characteristics show the rectification ratio of about 103 and the leakage current of about 10−4 A/cm2 at room temperature. From the capacitance-voltage measurements the free carrier concentration in GaN NWs is determined as about 1016 cm−3. Two deep levels (H200 and E280) are found in the structures containing GaN NWs. H200 is attributed to an extended defect located at the interface between the substrate and SiNx or near the sidewalls at the bottom of the NWs whereas E280 is tentatively assigned to a gallium-vacancy- or nitrogen interstitials-related defect.