Photoresponse of Zinc oxide thin-film transistors with location-controlled crystal grains fabricated by low-temperature hydrothermal method

Zinc oxide (ZnO) bottom-gate (BG) thin-film transistors (TFTs) with single vertical grain boundary in the channel have been successfully fabricated by a novel low-temperature (i.e. 85 °C) hydrothermal method. The proposed devices demonstrated the high field-effect mobility of 9.07 cm²/V·s, low threshold voltage of 2.25 V, high on/off current ratio above 10⁶, and superior current drivability, attributed to the high-quality ZnO channel with single grain boundary. Moreover, a stable and repeatable operation of dynamic photoresponse is observed for the location-controlled hydrothermally grown ZnO BG-TFTs.