Performance optimization of self-powered visible photodetectors based on Cu₂O/electrolyte heterojunctions

The performance of the self-powered photodetectors based on the Cu₂O/electrolyte heterojunctions is optimized by adjusting morphology and structure of the Cu₂O film. The Cu₂O film with a deposition time of 2000 s possesses a largest current density of 559.6 μ A/cm² under visible light illumination at zero bias, with a rising time of 5.2 ms and a recovering time of 9.0 ms. This optimized Cu₂O film has a highest responsivity of about 25.8 mA/W for visible light, and a negligible responsivity for UV light. The high crystallinity and excellent charge transfer property are responsible for the improved photodetection performance.