Ultraviolet photodetectors fabricated from ZnO p–i–n homojunction structures

Zinc oxide (ZnO) p–i–n structured ultraviolet (UV) photodetector has been constructed in this paper. The photodetector exhibits an obvious response to ultraviolet light at 0 V bias, which is a typical character of p–i–n structured photodetectors. The maximum responsivity of the photodetector, which is located at around 390 nm, is about 0.45 mA W−1 at 0 V bias, and the responsivity increases with increasing reverse bias voltage applied. The response decay time of the p–i–n structured photodetector is about 260 ns. This is the first report on ZnO p–i–n homojunction structured photodetectors to the best of our knowledge. Considering that p–i–n structure is the most promising configuration for high performance photodetectors, the results reported in this paper may provide a clue for high-performance ZnO based UV photodetectors.