Dual-band solar-blind UV photodetectors based on AlGaN/AlN superlattices

Herein, a metal–semiconductor-metal (MSM) structure dual-band solar-blind ultraviolet (UV) photodetector based on 60.5-period Al0.5Ga0.5N/AlN superlattices (SLs) is reported. The device exhibits distinct dominant responses in the solar-blind UV region with dual peaks located at 266 nm and 243 nm. The formation of dual-band solar-blind UV photodetection is clarified, which can be originated from the reflection enhancement property of the highly periodic Al0.5Ga0.5N/AlN SLs that restrains the light absorption around 259 nm resulting in weak spectral response in this specific waveband.