Eco-Friendly, Water-Induced In2O3 Thin Films for High-Performance Thin-Film Transistors and Inverters

Solution-driven metal-oxide semiconductors have recently received much attention as a viable option for low-cost, flexible electronic devices. In this paper, a simple, environmentally friendly aqueous solution method has been adopted to deposit an ultrathin In2O3 semiconductor layer with a thickness of about 7 nm at low temperature. Then, in combination with the advantages of atomic layer deposition (ALD) technology, an ultrathin aluminum oxide dielectric layer of about 20 nm was prepared to fabricate high-performance In2O3/Al2O3 thin-film transistor (TFT) devices. The device with optimized annealing temperature of 280 degrees C has demonstrated an excellent electrical performance, including a high saturation mobility of 11.85 cm(2) .V-1 . s(-1), a large ON/OFF current ratio of 10(6), a low threshold voltage of 0.12 V, a small hysteresis voltage of 0.05 V, and a small density of interface state of 1.97 x 10(12) cm(-2), respectively. To demonstrate the potential of In2O3/AlOx TFT toward more complex logic applications, the unipolar inverter was further constructed and exhibited a high gain of 5. Importantly, all these device parameters were obtained at an ultralow operating voltage of 2.5 V. As a result, it can be inferred that the water-induced In2O3 TFTs based on ALD-derived Al2O3 dielectrics have a potential application as a promising alternative for lowcost, low-power consumption, and large-area environmentally friendly oxide flexible electronics.