High-performance fully amorphous bilayer metal-oxide thin film transistors using ultra-thin solution-processed ZrOx dielectric

In this study, we report high-performance amorphous In₂O₃/InZnO bilayer metal-oxide (BMO) thin-film transistor (TFT) using an ultra-thin solution-processed amorphous ZrO_x dielectric. A thin layer of In₂O₃ offers a higher carrier concentration, thereby maximizing the charge accumulation and yielding high carrier mobility. A thick amorphous layer of InZnO controls the charge conductance resulting in low off-state current and suitable threshold voltage. As a consequence, the BMO TFT showed higher filed-effect mobility (37.9 cm²/V s) than single-layer InZnO TFT (7.6 cm²/V s). Apart from that we obtain an on/off current ratio of 10⁹, a subthreshold swing voltage of 120 mV/decade, and a voltage shift ≤ 0.4 V under positive bias stress for 2.5 h, for a gate voltage of 3 V and drain voltage of 1 V. These data demonstrate that the BMO TFT has great potential for a broad range of applications as switching low-power transistors.