Transparent ZnO thin film transistor fabricated by sol-gel and chemical bath deposition combination method

Top-gate thin film transistors with n-type ZnO active channel were performed under 230°C. Especially, ZnO film was deposited by a combined method of sol-gel and chemical bath deposition without any preactivation for film growth. Silicon nitride and indium tin oxide were used as the gate insulator and the conducting electrodes (source, drain, and gate). These transistors were highly transparent in the visible spectrum, with transmittance as high as 75% to approximately 85% at wavelength from 500to700nm. The optimum device has field-effect mobility of 0.67cm2∕Vs and an on-off ratio more than 107.