ZnO Nanowires Growth from Thin Zinc Films for Field Emission Purposes

Zinc oxide (ZnO) has attracted considerable interest for a wide range of applications, including its use as an active layer in gas sensor devices and as promising emitters for field emission devices. This paper explores ZnO nanowires growth through thermal oxidation of zinc thin films deposited over glass substrates. We applied this low-complexity IC-compatible procedure for fabricating field emission cathodes. Raman Spectroscopy and Scanning Electron Microscopy show that the processes applied succeeded in obtaining nanoscale structures of ZnO with dimensions up to 4 micrometers in length and 30-100 nanometers in diameter. This study also investigated field emission characteristics of these ZnO nanowires. Electrical characterization showed an intense electron field emission with good uniformity of the emitted current on the active area of the device, with a low turn-on electric field (2.4 volts/micrometer). These results demonstrate that the low-complex fabrication procedures adopted as well as the ZnO nanomaterial itself are suitable for FE devices development.