Investigation of the effects of Mg incorporation into InZnO for high-performance and high-stability solution-processed thin film transistors

We have fabricated high-performance and high-stability sol-gel-processed MgInZnO thin films transistors with varying Mg content. As the Mg content was increased, the turn-on-voltage increased and the off-current decreased. This is because the incorporation of Mg (with low standard electrode potential and high optical band gap, E_opt, when oxidized) causes reduction in the oxygen vacancy, acting as a carrier source, and an increase in E_opt of the film. This results in reduction in carrier concentration of the film. Small grains and smooth morphology by varying the Mg content lead to an improvement of the mobility, on-current, and subthreshold gate swing.