High Performance Ultrathin SnO 2 Thin-Film Transistors by Sol–Gel Method

Sol–gel processed ultrathin nanostructured SnO 2 thin-film transistors were successfully fabricated on a SiO 2 /Si substrate without using a self-aligned monolayer or high- ${k}$ insulator, which may be unsuitable techniques for the commercial fabrication of complementary metal–oxide–semiconductors. The highest extracted field mobility was approximately 100 cm 2 /V $\cdot$ s. In addition, by controlling the SnO 2 film thickness, we successfully increased the on/off current ratio to ~10 7 . The electrical performance of the proposed transistors is sufficient for high-resolution liquid crystal or organic light-emitting diode displays, which require a high field-effect mobility (>10 cm 2 /V $\cdot$ s) and high on/off current ratio (>10 6 ). Ultrathin SnO 2 is also a promising rare-metal-free starting matrix for ternary and quaternary alloys, showing promising electric properties.