Self-powered solar-blind deep-UV photodetector based on CuI/Ga2O3 heterojunction with high sensitivity

In this work, a high-performance self-powered deep-ultraviolet (UV) CuI/Ga2O3 heterojunction photodetector was proposed by pulsed laser deposition (PLD) and vacuum thermal evaporation method. The device is particularly responsive to 254 nm deep-UV illumination as well as exhibits excellent and stable self-powered performance with an on-off ratio of 1 × 104, R of 1.44 mA/W and D* of 5.94 × 1011 Jones at 0 V bias. Even under weak deep-UV light of 2.7 μW·cm−2, the device still exhibits outstanding photo-response properties with D* of 1.76 × 1012 Jones. The photodetector exhibits superior performance compared to other previously reported self-powered photodetectors based on Ga2O3. Our work offers great potential to fabricate deep-UV detection devices with high sensitivity. [Display omitted] •Solar-blind photodetector based on CuI/β-Ga2O3 heterostructure has been successfully designed.•The dark current and response speed of the photodetector are significantly improved by introducing a CuI layer.•The photodetector exhibits a self-powered behavior with D* of 1.76 × 1012 Jones under weak deep-UV light.