ZnO homojunction ultraviolet photodetector based on p-type dual-doped film and n-type nanorods

ZnO:(Ag,N)/ZnO p–n homojunction was fabricated by depositing a ZnO:(Ag,N) film on vertically aligned ZnO nanorods (NRs). The homojunction is able to work as a self-powered device due to the photovoltaic effect, and the ZnO NRs play an important role in the photovoltaic conversion process. Current–voltage (I–V) characteristic shows a turn-on voltage of ∼3 V and a rectification ratio of 1.3 × 102 at 5 V. Spectral responsivity exhibits an UV-to-visible rejection ratio of 1 × 102. The photocurrent rise and decay times are 7 and 45 ms, respectively. These results indicate the ZnO:(Ag,N)/ZnO homojunction is an attractive candidate for high-performance self-powered UV photodetectors.