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 cm 2  V −1  s −1 , and a current on/off ratio of 10 4 –10 5 . 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.