Single nanowire AlN/GaN double barrier resonant tunneling diodes with bipolar tunneling at room and cryogenic temperatures

III-N semiconductor resonant tunneling diodes (RTDs) have attracted great research interest because of their potential high speed performance. Thin film III-N RTDs are challenging due to high dislocation densities resulted from large lattice and thermal expansion coefficient mismatches to substrates. Here the authors present the growth and fabrication of AlN/GaN double barrier nanowire RTDs. The AlN/GaN double barrier nanowire RTDs show clear negative differential resistance with an onset voltage between 3.5 V and 4.5 V at both room and cryogenic temperatures. The bipolar tunneling and temperature dependent device performance suggest that the electron transport of these devices is based on resonant tunneling.