High response Schottky ultraviolet photodetector formed by PEDOT:PSS transparent electrode contacts to Mg_0.1Zn_0.9O

In this paper, we report a Schottky ultraviolet photodetector based on poly (3,4-ethylenedioxy-thiophene) poly(styrenesulfonate) (PEDOT:PSS) transparent electrode contacts to Mg_0.1Zn_0.9O. 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 photo-to-dark current ratio is high, which is 1× 10³ at -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.