High-Performance Thin-Film Transistors with Aqueous Solution-Processed NiInO Channel Layer

We report the aqueous-solution-processed Ni-doped In2O3 (Ni x In2–x O3, NiInO) thin-film transistors (TFTs) for the first time. The effect of Ni doping on In2O3 microstructure, oxygen defects, and the electron transport properties are investigated by extensive characterization techniques. Analyses indicate that the oxygen vacancies in NiInO are suppressed as the Ni-doping concentration increases, leading to a lower off-state current and a positive shift in threshold voltage. The optimized NiInO TFTs exhibit a high mobility of 17.71 cm2/(V s), on/off current ratio > 106, threshold voltage of 4.21 V, and superior bias stress stability. The success of Ni doping could be attributed to the small ion radius of Ni, large Lewis acid value, and strong Ni–O bond strength. Therefore, the fabricated NiInO TFT provides a bright path for the development of high-performance oxide TFTs.