Ambient Constancy of Passivation-Free Ultra-Thin Zinc Tin Oxide Thin Film Transistor

An ultra-thin (5 nm-thick), unpassivated zinc tin oxide (ZTO) thin-film transistor TFT, fabricated with solution process, exhibits a good field-effect mobility (13 similar to 14 cm(2)/Vs), small subthreshold swing (similar to 0.30 V/dec.) and high on/off current ratio (similar to 10(8)). The field-effect mobility can be further enhanced by increasing the ZTO thickness to 12 nm and 22 nm. Furthermore, I-D-V-G characteristics of the 5 nm-thick ZTO TFT remain unaffected, regardless of working in air (60% relative humidity), vacuum or dry O-2 atmosphere. The dissimilar TFT characteristics are discussed in terms of oxygen deficiency content, as well as the Fermi level position (E-F to E-C) for ZTO of various thicknesses to explain the moisture immunity of the 5 nm-thick solution-processed ZTO TFT. (C) The Author(s) 2015. Published by ECS. All rights reserved.