Environmentally stable/self-powered ultraviolet photodetectors with high sensitivity

Here, we demonstrate self-powered ultraviolet photodetectors that are capable of generating opposite current flow when illuminated at different wavelengths. The photodetectors are composed of n-ZnO/Polyaniline (PANI) p-n and PANI/ZnGa2O4 type-II heterojunctions and operate without any need for external power source. Devices display superior stability in ambient conditions within months. Results provide opportunities for developing devices for optical recognition. (C) 2013 AIP Publishing LLC.