Improvement in the Performance of Sol-Gel Processed In₂O₃ Thin-Film Transistor Depending on Sb Dopant Concentration

Solution-processed Sb-doped In₂O₃ thin-film transistors (TFTs) have been fabricated. To improve the electrical performance, In₂O₃ was doped with Sb, which exhibits a higher standard electrical potential than In and acts as a booster to create more oxygen vacancies and extra electrons. We observed that as the doping concentration increases, the oxygen deficiency of In₂O₃ and the concentration of Sb⁵⁺ increases, leading to an increase in the field-effect mobility. Doping with an appropriate amount of Sb resulted in a significant improvement of the field-effect mobility of TFTs. A TFT exhibiting a high mobility of 1.6 cm²/Vs and an ON/OFF current ratio of 10⁴ was obtained. A field-effect mobility of ten times higher than that of single In₂O₃ TFTs was achieved.