Solution-processed indium-zinc-oxide thin-film transistors based on anodized aluminum oxide gate insulator modified with zirconium oxide

Abstract

Solution-processed indium-zinc-oxide (IZO) thin-film transistors (TFTs) based on anodized aluminum oxide gate insulator modified with a zirconium oxide (ZrO_x) interlayer were fabricated. By introduction of the ZrO_x interlayer, the IZO-TFTs exhibited improved performance with a higher mobility of 7.8 cm² V⁻¹ s⁻¹, a lower V_th of 4.6 V and a lower SS of 0.21 V dec⁻¹ compared to those without the ZrO_x interlayer. Comprehensive studies showed that the Al element easily diffused into the IZO film and formed AlO_x clusters which acted as defects to deteriorate TFT performance; and after modification with a ZrO_x interlayer, the diffusion of Al was suppressed and the Zr diffusing effect almost could be ignored. These results suggested that the introduction of an interlayer with less diffusing effect as well as an effect of blocking the elements from the gate insulator diffusing into the channel layer could be an effective way to improve the electrical performance for solution-processed oxide TFTs.