Multifunctional optoelectronic device based on CuO/ZnO heterojunction structure

Combining ZnO materials and other narrow bandgap materials is an effective route to construct high performance optoelectronic devices. Herein, a multifunctional optoelectronic device based on CuO/ZnO p-n junction was prepared by growing ZnO nanorod arrays on CuO film. The obtained device not only can be used as self-powered photodetector in a wide spectral range, but also as a photo-induced binary response device. The obtained self-powered photodetector can operate in UV–vis–NIR region. The maximum responsivity of 1.24 μA∙W −1 , specific detectivity of 9.77 × 10 6 Jones, and response/recovery time of ∼20 ms were achieved at zero bias when the device was irradiated by 405 nm light (55 mW cm −2 ). The thickness of CuO film has significant influence on the performance of photodetectors. The built-in field at the interface of CuO and ZnO makes the device operate without any external power supply. The obtained device also exhibits a photo-induced binary response characteristic at a small forward bias, showing great application potential in light communication systems and optical chips.