Highly stable InZnSnTbOX thin-film transistors

Abstract

The trade-off between mobility and stability in oxide thin-film transistors (TFTs) has limited the applications for high-resolution displays. Herein, a multicomponent InZnSnTbOX (IZTTO) thin film is rationally designed as channel to enhance the electrical stability and achieve high mobility in TFTs. Correspondingly, the mechanism of terbium doping is further investigated. In-rich InZnSnOX favors big ns orbital overlap area of cations and effective edge-shared structures for high carrier transport. As the carrier concentration and defects density of the channel can be effectively modulated by incorporating Tb, TFTs exhibit a high mobility of 24.8 cm2/V·s with a low subthreshold swing of 112 mV/dec. Notably, the bias-illumination stability and high-temperature reliability are significantly improved, due to the charge transfer transition between Tb ions and ligand affords to short relaxation time of delocalized electron, in which a threshold voltage shift (ΔVTH) of −1.6 V is obtained under negative bias illumination stress for 3600 s, and a ΔVTH of 0.6 V is obtained under positive bias temperature stress (PBTS) for 3600 s at 360 K.