Study on ZnO-based Thin Film Transistors

Zinc oxide is a wide band gap optoelectronic semiconductor material, it can be applied in many fields, such as varistors, surface acoustic waves, gas sensors, UV detectors and so on. Zinc oxide can also be used in thin film transistors as an active layer. ZnO TFT has many excellent characteristics. The average optical transmission in the visible part of the spectrum is more than 80 %. The field effect mobility is as large as 36 cm~2/V·s. I_ on /I_ off ratio is more than 10~6. ZnO TFT can be manufactured at a low temperature (or even at room temperature). Therefore, ZnO TFT has the potential to take the place of conventional a-Si TFT in active-matrix liquid crystal displays. Meanwhile, study on ZnO TFT has motivated considerable development on transparent electronics. In this paper, electrical advantages, as well as some defects of ZnO TFT are described, and then an expectation of its future application is given.