Fastly steady UV response feature of Mn-doped ZnO thin films

When the conventional zinc oxide film is used as an ultraviolet detector, it has the disadvantages of slow response time, unstable signal. In order to solve this problem, Mn-doped ZnO films (MZO) were prepared by sol-gel method in this work. Results show that Mn doping can cause deterioration of crystal quality, photocurrent and dark current will decrease at the same time, but in low doping mode (1.5 at.%), the response time of the film can be greatly improved (from about 100 s to 10 s), and the photocurrent is very stable. Moreover, since the dark current is simultaneously weakened, the signal-to-noise ratio is not significantly reduced and is still acceptable. Further increasing the doping concentration, the photocurrent and the dark current continue to decrease. Although a faster photoelectric response is obtained, since the photocurrent is too weak, the electrode is extracted more than the rate at which the photocurrent is generated, and the photocurrent has a tendency to decrease.