Investigation of the negative differential resistance reproducibility in AlN/GaN double-barrier resonant tunnelling diodes

Abstract

AlN/GaN double-barrier resonant tunnelling diodes were grown by molecular beam epitaxy on GaN/sapphire template and processed into mesa diameters from 2 m to 4 m. The current-voltage characteristics were carried out in direct current operation and under-high vacuum. A sharp negative differential resistance (NDR) was detected in the forward bias at 120 K. The NDR was observed for the mesa size of 2 m at 4 V with a peak-to-valley current ratio of 3.5. The measurement conditions were chosen to make NDR reproducible more than 50 times and apparent in both scan voltage directions after electrical treatment. © 2011 American Institute of Physics.