High-performance enhancement-mode thin-film transistors based on Mg-doped In2O3 nanofiber networks

Although In 2 O 3 nanofibers (NFs) are well-known candidates as active materials for next-generation, low-cost electronics, these NF based devices still suffer from high leakage current, insufficient on–off current ratios ( I on / I off ), and large, negative threshold voltages ( V TH ), leading to poor device performance, parasitic energy consumption, and rather complicated circuit design. Here, instead of the conventional surface modification of In 2 O 3 NFs, we present a one-step electrospinning process (i.e., without hot-press) to obtain controllable Mg-doped In 2 O 3 NF networks to achieve high-performance enhancement-mode thin-film transistors (TFTs). By simply adjusting the Mg doping concentration, the device performance can be manipulated precisely. For the optimal doping concentration of 2 mol%, the devices exhibit a small V TH (3.2 V), high saturation current (1.1 × 10 –4 A), large on/off current ratio (>10 8 ), and respectable peak carrier mobility (2.04 cm 2 /(V·s)), corresponding to one of the best device performances among all 1D metal-oxide NFs based devices reported so far. When high- κ HfO x thin films are employed as the gate dielectric, their electron mobility and V TH can be further improved to 5.30 cm 2 /(V·s) and 0.9 V, respectively, which demonstrates the promising prospect of these Mg-doped In 2 O 3 NF networks for highperformance, large-scale, and low-power electronics.