The Study for Solution-Processed Alkali Metal-Doped Indium–Zinc Oxide Thin-Film Transistors

High-performance alkali metals-doped indium–zinc oxide (IZO) thin-film transistors (TFTs) were prepared by the sol–gel process. With appropriate doping concentration of alkali metals, both the field-effect mobility and bias stress stability could be improved, because alkali metals doping could increase electron concentrations, improve interface quality, and significantly reduce oxygen vacancy defect states in the active channel layer of IZO TFTs. In particular, the 10-mol% Li-doped IZO TFTs with a maximum field-effect mobility of 34.5 cm
²
/
$\textrm {V}{\cdot }~\textrm {s}$
and an improved bias stress stability were obtained. Our results demonstrate the doping mechanism of alkali metals in IZO films and represent an effective strategy by employing alkali metals to achieve high-performance solution-processed IZO-based TFTs.