Electronic properties of ZnO field-effect transistors fabricated by spray pyrolysis in ambient air

We report the application of spray pyrolysis (SP) for the deposition of high quality zinc oxide (ZnO) films and the fabrication of thin-film transistors. The chemical, structural, optical, and electronic properties of as-deposited ZnO films are studied using infrared spectroscopy, atomic force microscopy, UV-visible spectroscopic ellipsometry, and field-effect measurements. SP ZnO films are found to be uniform and polycrystalline with a band gap of 3.32 eV. ZnO transistors exhibit n-channel characteristics with electron mobility in the range 10–22 cm2/Vs. Device performance is found to depend on the work function of source/drain metal electrodes and on the device architecture employed.