Water-based processed and alkoxide-based processed indium oxide thin-film transistors at different annealing temperatures**Project supported by the National Natural Science Foundation of China (Grant No. 61675024) and the National Basic Research Program of China (Grant No. 2014CB643600).

Abstract

In this study, indium oxide (In2O3) thin-film transistors (TFTs) are fabricated by two kinds of low temperature solution-processed technologies (), i.e., water-based (DIW-based) process and alkoxide-based (2-ME-based) process. The thickness values, crystallization properties, chemical structures, surface roughness values, and optical properties of In2O3 thin-films and the electrical characteristics of In2O3 TFTs are studied at different annealing temperatures. Thermal annealing at higher temperature leads to an increase in the saturation mobility (μsat) and a negative shift in the threshold voltage (VTH). The DIW-based processed In2O3-TFT annealed at 300 °C exhibits excellent device performance, and one annealed at 200 °C exhibits an acceptable μsat of 0.86 cm2/V·s comparable to that of a-Si:H TFTs, whereas the 2-ME-based TFT annealed at 300 °C exhibits an abundant μsat of 1.65 cm2/Vs and one annealed at 200 °C is inactive. The results are attributed to the fact that the DIW-based process induces a higher degree of oxidation and less defect states than the 2-ME-based process at the same temperature. The DIW-based process for fabricating the In2O3 TFT opens the way for the development of nontoxic, low-cost, and low-temperature oxide electronics.