Correlation between alkaline-earth-metal dopants and threshold voltage (Vth) stability of solution-processed gallium indium oxide thin film transistors

Abstract

We examined solution-processed alkaline-earth-metal doped gallium indium oxide (GIO) thin film transistors (TFT) and studied the relationship between the dopant species and the threshold voltage (Vth) stability. As the atomic number of the dopant increases, the amount of oxygen vacancies, which act as the major defect sites, decreased and the Vth stability is enhanced. The electron trapping times and total defect sites were quantitatively calculated. Particularly, Sr-doped GIO TFT show the highest Vth stability under positive gate bias and the origin of Vth stability enhancement is deduced by using the partial charge model and reaction kinetics.