High Annealing Stability of InAlZnO Nanofiber Field-Effect Transistors with Improved Morphology by Al Doping

In₂O₃ nanofibers usually suffer a high off-current and consequent low on/off current ratio, as well as a large negative threshold voltage (V_th). Furthermore, regarding Zn doped binary-cation In₂O₃ nanofibers, severe thermal diffusion of Zn elements can result in deteriorated electrical performance when annealed at high temperature. Here, we applied an electrospinning technique to obtain ternary-cation IAZO nanofibers with controllable V_th and chemical stoichiometry. The presence of the Al element in IAZO nanofibers can lead to more superior microstructure with improved uniformity, lower surface defect, and superior metal-oxide-metal lattice at high annealing temperature. Consequently, our Al-doped ternary-cation IAZO devices exhibited an improved on/off current ratio of 10⁷ and a high electron mobility of ∼10 cm² V^-1 s^-1. Moreover, the electron mobility can be increased to 30 cm² V^-1 s^-1 in our low-voltage operated FETs with high-k AlO as the dielectric layer, which can be envisioned to exhibit vast implications for high-performance transparent electronics.