Development of Al Doped ZnO Nanowalls Based Flexible, Ultralow Voltage UV Photodetector

We report an Al-doped ZnO nanowalls network based ultralow voltage, flexible UV photodetector (PD). The PD is synthesized over an Al foil by using a simple and low-cost hydrothermal process. The device has shown photocurrent to a dark-current ratio of 349, high responsivity (265 mA·W-1 at just 0.1 V applied bias), and specific detectivity of 4.5 × 1010 cm·Hz1/2·W-1 at 350 nm. The incident light power has been kept as low as 396 μW·cm-2 throughout the measurements. The external quantum efficiency was 1827.8% at 5 V applied bias. The proposed ultralow voltage UV PD demands very low power and, therefore, could potentially lengthen the battery discharge time. Additionally, a prominent UV sensitive piezoelectric response, having dark voltage to photo voltage ratio of 24.5, has been demonstrated that has made the device a potential candidate for fast response time, self-powered PD.