Ultraviolet light sensitive In-doped ZnO thin film field effect transistor printed by inkjet technique



This indium-doped zinc oxide field effect transistor (IZO-FET) with a large ultraviolet (UV) detection sensitivity has been fabricated by inkjet printing technique. In darkness, the IZO-FETs exhibit a saturation current level of about 10 µA, an incremental mobility as high as 8 cm2 V−1 s−1, and a current on/off ratio of 104–105. When illuminated by 363 nm, 1.7 mW cm−2 UV light, the IZO-FET displays a photocurrent of 2 mA, and a darkness current of ∼20 nA at an optimized gate voltage of −2 V. The device is effectively turned on in about 5 ms and off in 10 ms. These results suggest that the IZO-FET fabricated by inkjet printing could be a low cost highly sensitive UV photodetector.