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

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 10(3) and the leakage current of about 10(-4) A/cm(2) at room temperature. From the capacitance-voltage measurements the free carrier concentration in GaN NWs is determined as about 10(16) 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. (C) 2013 AIP Publishing LLC.