Comprehensive Study of Improved Negative-Bias-Illumination-Temperature Stress Stability in Terbium-Doped Indium-Zinc-Oxide Thin-Film Transistors

In this study, the explanation of the enhanced negative-bias-illumination-temperature stress stability (NBITS) of indium-zinc-oxide thin-film transistors (IZO TFTs) under terbium (Tb) doping is addressed. The acquired Tb-IZO TFTs exhibit enhanced stability compared with pristine device ( $\Delta {V}_{\text {th}}$ after NBITS decreased from−4.1 to −0.6 V). Hall measurements, X-ray photoelectron spectroscopy, and microwave photoconductivity decay were used to analyze the impact of Tb doping on the characteristics of metal–oxide–semiconductor films. It is believed that Tb-induced shallow defects may serve as the recombination centers for capturing photo-generated electrons, which is an essential complement to the trap-assisted model. The optimized Tb content is considered to be 3.21 at.%, with a mobility of 20.0 cm ² / $\text{V}\cdot \text{s}$ , ${I}_{ \mathrm{\scriptscriptstyle ON}}/{I}_{ \mathrm{\scriptscriptstyle OFF}}$ ratio of $10^{{9}}$ , and an NBITS of −0.8 V.