Achieving high mobility and enhanced illumination stability in InPrO homojunction thin-film transistors

Abstract

Amorphous oxide semiconductor thin-film transistors (TFTs) are widely used in display technology, yet balancing high mobility with illumination stability is challenging. In this article, we report a homojunction TFT based on Pr-doped In2O3 (InPrO), where the oxygen partial pressure is modulated to control device's mobility and stability significantly. Combining the characteristic of enhanced mobility at low oxygen partial pressure and the enhanced recombination role of Pr at high oxygen partial pressure, compatibility between high mobility and high illumination stability is achieved. This InPrO homojunction TFT exhibits excellent electrical characteristics, including a mobility of 50 cm2/Vs, a threshold voltage of 0.1 V, an Ion/off of 108, and a subthreshold swing of 0.1 V/dec. It also demonstrates enhanced stability, with threshold voltage shifts of −0.6 V for negative bias stress, 1.0 V for positive bias stress, and −0.9 V for negative bias illumination stress. This work provides a pathway for advancing AOS TFTs in transparent display technologies.