Exploring the Effect of Dy Doping on the Performance of Solution-Processed Indium Oxide Thin Films and Thin-Film Transistors

In this study, we prepared Dy-doped indium oxide (In2O3) thin-film transistors (TFTs) using a solution-based method. We conducted a comprehensive investigation into the effects of Dy doping concentration on the structure, surface morphology, optical properties, and energy band structure of In2O3 thin films. Additionally, we explored the relationship between the electrical characteristics of the TFTs and the Dy doping concentration. Our findings include achieving a high mobility of 11.35 cm2/V<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\cdot $ </tex-math></inline-formula> s, a threshold voltage of 2.07 V, a current switching ratio of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1.89\times 105$ </tex-math></inline-formula>, and a low subthreshold swing (SS) of 0.49 V/dec. These results indicate that appropriate Dy doping can enhance the crystallization temperature and band gap of In2O3 films. X-ray photoelectron spectroscopy (XPS) and electrical characterization results demonstrate that Dy acts as a carrier suppressor, effectively reducing the carrier concentration and passivating oxygen vacancy defects in the active/insulating layer channel and the interface trap state density. This also causes a positive shift in the threshold voltage. Therefore, DyInO TFTs show great potential for application in transparent electronics and flat-panel displays in the future.