N-polar GaN/AlN resonant tunneling diodes are realized on single-crystal N-polar GaN bulk substrate by plasma-assisted molecular beam epitaxy growth. The room-temperature current-voltage characteristics reveal a negative differential conductance (NDC) region with a peak tunneling current of 6.8± 0.8 kA/cm2 at a forward bias of ~8 V. Under reverse bias, the polarization-induced threshold voltage is measured at ~−4 V. These resonant and threshold voltages are well explained with the polarization field which is opposite to that of the metal-polar counterpart, confirming the N-polarity of the RTDs. When the device is biased in the NDC-region, electronic oscillations are generated in the external circuit, attesting to the robustness of the resonant tunneling phenomenon. In contrast to metal-polar RTDs, N-polar structures have the emitter on the top of the resonant tunneling cavity. As a consequence, this device architecture opens up the possibility of seamlessly interfacing−via resonant tunneling injection−a wide range of exotic materials with III-nitride semiconductors, providing a route to explore new device physics.
@article{arxiv.2010.03079,
title = {N-polar GaN/AlN resonant tunneling diodes},
author = {YongJin Cho and Jimy Encomendero and Shao-Ting Ho and Huili Grace Xing and Debdeep Jena},
journal= {arXiv preprint arXiv:2010.03079},
year = {2020}
}