High‐Performance Nd: AIZO/Al₂O₃ Dual Active Layer Design Without Thermal Annealing: High‐Speed Electron Transport and Defect Modification in Thin Film Transistors

Flexible wearable electronics have been developing rapidly in recent years, and one of its core devices, thin‐film transistor (TFT), is also attracting attention. Current TFT preparation processes usually require high annealing temperatures (>350 °C), which is not conducive to their application on most flexible substrates (PET, PEN, nanopaper, etc.). In this article, a strategy for the room temperature preparation of Nd:AIZO/Al₂O₃ dual‐layer TFT devices is proposed, which has appreciable electrical properties without additional annealing treatment. Taguchi orthogonal experimental methods are used to investigate the effects of three essential process parameters on the performance of the films and devices. As Nd:AIZO deposition time decreases and Al₂O₃ oxygen percentage and time during deposition increase, the μ_sat and SS of TFT devices are improved. With the preferred combination of parameters applied to the device preparation, the device exhibits a saturation mobility μ_sat of 24.3 cm² V⁻¹ s⁻¹, a threshold voltage V_th of −1.4 V, a subthreshold swing SS of 0.21 V decade⁻¹ and an I_on/I_off ratio of 4.26 × 10⁸. The ultra‐thin Al₂O₃ layer act as defect modification and form high‐speed electron transport in channel layer. The room temperature preparation of the dual‐layer TFT process proposed in this article is compatible with large‐size low‐cost flexible substrates. It has great potential for application in green flexible wearable electronics.