Bias Stress Stability of Solution-Processed Nano Indium Oxide Thin Film Transistor

In this paper, the effects of annealing temperature and other process parameters on spin-coated indium oxide thin film transistors (In₂O₃-TFTs) were studied. The research shows that plasma pretreatment of glass substrate can improve the hydrophilicity of glass substrate and stability of the spin-coating process. With Fourier transform infrared (FT-IR) and X-ray diffraction (XRD) analysis, it is found that In₂O₃ thin films prepared by the spin coating method are amorphous, and have little organic residue when the annealing temperature ranges from 200 to 300 °C. After optimizing process conditions with the spin-coated rotating speed of 4000 rpm and the annealing temperature of 275 °C, the performance of In₂O₃-TFTs is best (average mobility of 1.288 cm²·V^-1·s^-1, I_on/I_off of 5.93 × 10⁶, and SS of 0.84 V·dec^-1). Finally, the stability of In₂O₃-TFTs prepared at different annealing temperatures was analyzed by energy band theory, and we identified that the elimination of residual hydroxyl groups was the key influencing factor. Our results provide a useful reference for high-performance metal oxide semiconductor TFTs prepared by the solution method.