Double-Barrier Resonant Tunnel Heterostructures for High-Performance Terahertz Detection

Terahertz quantum well photodetectors (THz QWPs) have demonstrated high sensitivity and rapid response speeds, yet their practical applications remain constrained by the requirement for cryogenic operating temperatures. To overcome this limitation, we propose a THz resonant tunneling quantum well photodetector (RT-QWP) incorporating a double-barrier structure. We systematically designed and characterized a 6.5 THz RT-QWP. Our results reveal that the double-barrier architecture in the RT-QWP effectively suppresses dark current while facilitating efficient photocurrent tunneling. This design achieves a nearly three-order-of-magnitude reduction in dark current compared to conventional THz QWPs. Owing to this significant dark current suppression, the background-limited infrared performance (BLIP) temperature is elevated from 16 to 22 K in contrast to a conventional THz QWP operating at the same response frequency. The specific detectivity is enhanced by a factor of 4.8. Such a resonant tunneling design provides a possible way to improve the overall performance of THz photodetectors.