High-performance negative differential resistance characteristics in homoepitaxial AlN/GaN double-barrier resonant tunneling diodes

In this work, high-performance negative differential resistance (NDR) characteristics are demonstrated in homoepitaxial AlN/GaN double-barrier resonant tunneling diodes (RTDs). The devices are grown by plasma-assisted molecular beam epitaxy on bulk GaN substrates and exhibit robust and repeatable NDR at room-temperature. High peak current density of 183 kA/cm2 is simultaneously demonstrated with a large peak-to-valley current ratio of 2.07, mainly benefiting from the significantly reduced dislocation density and improved hyper-abrupt heterointerfaces in the active region, which boosts the electron quantum transport in the resonant tunneling cavity. The achievement shows the promising potential to enhance the oscillation frequency and output power of GaN-based RTD oscillator, an imperative for next generation high-power solid-state compact terahertz oscillators application.