Fabrication of Sol Gel Solution-Based Zinc–Tin Oxide/Carbon Nanotube Hybrid Thin-Film for Thin-Film Transistors

Solution-processed oxide thin-film transistors (TFTs) can lead to a significant cost-effective process and suitable for large-scale fabrication. However, they often face limitations, such as lower field-effect mobility, the use of indium which is toxic and rare, and degradation compared to vacuum-based technologies. The single-walled carbon nanotubes (SWNTs) were incorporated with zinc-tin oxide (ZTO) precursor solution without dispersants for the device's active layer. Sol-gel solution-based ZTO/single-wall carbon nanotube (ZTO/SWNT) (TFTs) with various SWNT concentrations were fabricated to improve the performance of ZTO TFTs. ZTO TFTs containing SWNTs exhibited better electrical performance than those without SWNTs. Among the samples, the ZTO TFT with an SWNT concentration of 0.07 wt.% showed a field-effect mobility (μsat) of 13.12 cm²/Vs (increased by a factor of 3) and an I_on/I_off current ratio of 7.66 × 10⁷ with a lower threshold voltage. SWNTs in the ZTO/SWNTs acted as carrier transfer rods, playing a crucial role in controlling the electrical performance of ZTO TFTs. The proposed fabrication of a sol-gel solution-based process is highly compatible with existing processes because it brings ZTO/SWNT hybrid TFTs closer to practical application, opening up the possibilities for next-generation electronics in flexible devices and low-cost manufacturing.