Correlation between alkaline-earth-metal dopants and threshold voltage (V-th) 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 (V-th) stability. As the atomic number of the dopant increases, the amount of oxygen vacancies, which act as the major defect sites, decreased and the V-th stability is enhanced. The electron trapping times and total defect sites were quantitatively calculated. Particularly, Sr-doped GIO TFT show the highest V-th stability under positive gate bias and the origin of V-th stability enhancement is deduced by using the partial charge model and reaction kinetics.