In this paper, we report a Schottky ultraviolet photodetector based on poly(3,4-ethylenedioxy-thiophene)poly(styrenesulfonate)(PEDOT:PSS) transparent electrode contacts to Mg0.1Zn0.9O. The I–V characteristic curves of the device are measured in the dark condition and under the illumination of a 340-nm UV light. The device shows a typical rectifying behavior with a current rectification ratio of 103 at ±2 V, which exhibits a good Schottky behavior. The phototo-dark current ratio is high, which is 1×103at-4 V. A peak response of 0.156 A/W at 340 nm is observed. The device also exhibits a wide response from 250 nm to 340 nm, with a response larger than 0.1 A/W. It covers the UV-B region(280 nm–320 nm), which makes the device very suitable for the detection of UV-B light. In this paper, we report a Schottky ultraviolet photodetector based on poly (3,4-ethylenedioxy-thiophene) poly (styrenesulfonate) (PEDOT: PSS) transparent electrode contacts to Mg0.1Zn0.9O. The I-V characteristic curves of the device The device shows a typical rectifying behavior with a current rectification ratio of 103 at ± 2 V, which exhibits a good Schottky behavior. The phototo-dark current ratio is high, which is 1 × 103at-4 V. A peak response of 0.156 A / W at 340 nm is observed. The device also exhibits a wide response from 250 nm to 340 nm, with a response greater than 0.1 A / W. It covers the UV-B region (280 nm-320 nm), which makes the device very suitable for the detection of UV-B light.