Performances of transparent indium zinc oxide thin film transistors using ZrO_2 as dielectric processed by solution method

摘要

We report here the electrical and UV-photoelectrical performance of transparent indium zinc oxide (IZO) thin film transistors with solution-processed zirconia (ZrO_2) dielectric. The channel layers were deposited by magnetron sputter at room temperature. The ZrO_2 dielectric was deposited by solution process under ambient conditions followed by low temperature annealing. The films were structurally characterized by X-ray diffraction and atomic force microscope. Good device characteristics have been obtained with a field effect mobility of 30.7cm~2V~(-1)s~(-1), a current on/off ratio of 10~5, a threshold voltage of 0.8 V, and a sub-threshold swing of 30 mV decade~(-1). A resistor-load inverter was fabricated and shows reasonable transfer characteristics with a gain of about 5 at supply voltage of 2 V. It was observed that the transistors are sensitive to UV illumination. When exposed to ultraviolet light with an intensity of 120 μWcm~(-2), the photo-to-dark current ratio was more than 10~4 in the depletion region. All the above features make IZO thin film transistor a promising candidate to be also used as a UV-photo transistor.