Low-voltage ZnO thin-film transistors with high-K Bi1.5Zn1.0Nb1.5O7 gate insulator for transparent and flexible electronics

Abstract

We report on the fabrication of field-effect transistors with transparent oxide semiconductor ZnO serving as the electron channel and high-K Bi1.5Zn1.0Nb1.5O7 (BZN) as the gate insulator. The devices exhibited very low operation voltages (< 4 V) due to high capacitance of the BZN dielectric. The field effect mobility and the current on/off ratio were 0.024 cm(2)/V s and 2x10(4), respectively, at an operating voltage of 4 V. The threshold voltage and subthreshold swing were 2 V and 0.25 V/dec, respectively. The high optical transparency (> 80% for wavelength > 400 nm), low-temperature processing, and low operation voltage of ZnO-based thin-film transistors with integrated BZN dielectric offer a promising route for the development of transparent and flexible electronics. (c) 2005 American Institute of Physics.