Self-powered ZnO/SrCoOx flexible ultraviolet detectors processed at room temperature

Flexible and self-powered ultraviolet (UV) photodetectors can meet the growing demand of next-generation portable, light-weight optoelectronic devices and have attracted increasing attention in recent years. However, it is still challenging to develop self-powered UV detectors with high photosensitivity, fast response time, environment-friendly feature, as well as compatible to flexible substrates. Herein, thin film UV photodetectors based on inorganic ZnO/SrCoOx heterojunction are designed and fabricated on flexible polyimide substrate at room temperature. The built-in electric field between n-type ZnO and p-type SrCoOx films facilitates the separation and transportation of photogenerated carriers without any external bias. A high photosensitivity of (73.8 mA/W) and a quick response time (0.6/4.8 ms) at zero bias are realized under UV light illumination. Moreover, a long-term stability and a good flexibility are also demonstrated. This self-powered flexible UV photodetector fabricated at room temperature is a promising candidate for future energy-efficient, wearable and lightweight optoelectronic devices.