Highly responsive SnSe/GaN heterostructure-based UVC-SWIR broadband photodetector

Broadband photodetection spans the ultraviolet-C (250 nm) to shortwave-infrared (1250 nm) range is essential and desirable for various applications such as optical communication, spectral switching, and memory storage. We have utilized ultraviolet-responsive gallium nitride (GaN) and Tin selenide (SnSe) as the infrared-activated material to fabricate a broadband heterojunction-based optical detector. Through SnSe/GaN heterostructure, the fabricated detector combines GaN's ultraviolet to visible, with SnSe's visible to shortwave-infrared detectability. The device also possesses great responsiveness and a low dark current due to edge contact geometry, which directly accesses the heterostructure interface for both materials. The fabricated device functions well from the ultraviolet-C to the shortwave-infrared region, exhibiting the highest responsivity of 128 AW-1 and the lowest noise equivalent power of 5.2 × 10−14 WHz−1/2, the quantum efficiency ∼5 × 104% with a response time ∼800 μs for ultraviolet illumination while the highest responsivity of 6.06 AW-1 and noise equivalent power of 1 × 10−12 WHz−1 for the device under infrared illumination. The research will open up new possibilities for optoelectronic applications utilizing heterostructure-based wideband detection.