Solution-processed antimony-doped IGZTO thin-film transistors exhibiting superior operational stability under extreme environmental conditions†

Abstract

Amorphous oxide semiconductors (AOSs) have been widely utilized in display technologies due to their high carrier mobility, excellent uniformity, and low off currents. Conventional vacuum processing is limited by the high production costs and process complexity. The solution-based process offers a promising alternative but still faces challenges like low film density and instability. In this study, we propose Sb-doped indium–gallium–zinc–tin oxide (Sb:IGZTO) as an active layer material for solution-processed thin-film transistors (TFTs) to achieve simultaneous improvements in performance and stability. Sb⁵⁺ acts as a mobility enhancing dopant while also serving as an oxygen bonding agent, effectively suppressing oxygen vacancy (V_O) formation, thereby improving both the electrical characteristics and environmental stability of the TFTs. The fabricated Sb:IGZTO TFT(3%) exhibited a mobility of 16.43 cm² V⁻¹ s⁻¹, a subthreshold swing value of 0.374 V dec⁻¹, and on/off ratio of 1.67 × 10⁶. Furthermore, the devices demonstrated stable operation under various bias stress conditions. Notably, the Sb:IGZTO TFTs demonstrated excellent long-term stability retaining approximately 74.98% of their initial mobility after 90 days conducted at 85% relative humidity and 85 °C without additional passivation. These findings validate Sb⁵⁺ doping as an effective strategy to mitigate the trade-off between performance and stability in solution-processed oxide semiconductors.