Investigation of addition of silicon on the electrical properties of low temperature solution processed SiInZnO thin film transistor

Abstract

Silicon indium zinc oxide (SIZO) TFTs are prepared by solution process at low temperature. The SIZO TFTs were investigated with respect to optical, electrical properties and structure. The effect of silicon contents into an IZO TFTs were investigated as a function of silicon concentration from 0.01 to 0.4 mol%. The silicon has more oxidized than In or Zn due to the low standard electrode potential. As Si concentration increased, the threshold voltage shifted toward positive direction and the off current decreased, systematically. Silicon indium zinc oxide (SIZO) TFTs are prepared by solution process. Carrier generation originated from the oxygen vacancy could be modified by adding Si since Si could be an oxygen vacancy suppressor. This is also related with the origin of defect state which was observed to be involved with the creation of oxygen vacancies. The O-II/O-tot ratio was decreased as increase silicon doping contents, indicating that the addition of Si atoms decreases the carrier concentration due to the lack of oxygen vacancy act as major carrier in oxide TFTs. The Si molar ratios in the solution can effectively control carrier concentration and saturation mobility.