Improving Deposition Density of Solution Processed Carbon Nanotubes by Substrate Treatment for High-Performance Flexible Thin Film Transistors

Carbon Nanotubes (CNTs) are a promising semiconducting material for flexible electronics due to the exceptional mechanical and electrical properties. However, there is a significant performance gap between CNT thin-film transistors (TFTs) fabricated on flexible substrates and those on rigid substrates, which has greatly hindered their practical application. In this article, we investigate the influence of substrate hydrophilicity on deposited CNT density. Furthermore, a substrate treatment technique compatible with TFT manufacturing processes, the ultraviolet ozone (UVO) treatment, was proposed to enhance the deposited CNT density on flexible substrates. Based on this technique, we fabricate flexible CNT TFTs exhibiting a carrier mobility of 41.5 ± 7.84 cm$^{{2.}}\text{V}^{ {-{1}.}}\text{s}^{-{1}}$, which exceeds the performance of most previously reported flexible CNT TFTs and is even comparable to that fabricated on rigid silicon substrates. This approach will effectively promote the device performance of flexible CNT TFTs and provide important potentials for their practical application in high-performance flexible circuits.