Metal oxide semiconductors doped with additional inorganic cations have insufficient electron mobility for next-generation electronic devices so strategies to realize the semiconductors exhibiting stability and high performance are required. To overcome the limitations of conventional inorganic cation doping to improve the electrical characteristics and stability of metal oxide semiconductors, we propose solution-processed high-performance metal oxide thin-film transistors (TFTs) by incorporating polyaniline (PANI), a conductive polymer, in a metal oxide matrix. The chemical interaction between the metal oxide and PANI demonstrated that the defect sites and crystallinity of the semiconductor layer are controllable. In addition, the change in oxygen-related chemical bonding of PANI-doped indium oxide (InOx) TFTs induces superior electrical characteristics compared to pristine InOx TFTs, even though trace amounts of PANI are doped in the semiconductor. In particular, the average field-effect mobility remarkably enhanced from 15.02 to 26.58 cm2 V-1 s-1, the on/off current ratio improved from 108 to 109, and the threshold voltage became close to 0 V actually from -7.9 to -1.4 V.
Keywords: conductive polymer; metal oxide; organic doping; polyaniline; thin-film transistor.