Ultraviolet photoconductive detector with high visible rejection and fast photoresponse based on ZnO thin film

In this study, metal–semiconductor–metal (MSM) photoconductive detector was fabricated on c-axis preferred oriented ZnO film prepared on quartz by radio frequency magnetron sputtering. With the applied bias below 3 V, the dark current was below 250 nA. The typical responsivity peaked at around 360 nm, and had values of 30 A/W. In addition, the UV (360 nm) to visible (450 nm) rejection ratio of around five orders could be extracted from the spectra response. Furthermore, the transient response measurement revealed fast photoresponse with a rise time of 20 ns.