Channel Length Scaling of Solution-Processed Single-Walled Carbon Nanotube Thin-Film Transistors

Single-walled carbon nanotube (SWCNT) thin-film transistors (TFT) represent a cost-effective and performant alternative to traditional transistors in microfabrication and flexible electronics. In this study, SWCNT TFTs were fabricated using an improved low-cost solution-based approach to quantitatively characterize the impacts of channel length variations, as well as observe the impacts related to other parameters in SWCNT TFTs, such as the ON/OFF ratio and field-effect mobility. Silver-based electrodes with various channel lengths were created using inkjet printing. Preliminary data acquired with the solution-based approach shows promising results, with high drain current values and field-effect mobility values up to 42.4 cm
²
/Vs. The challenges involving the fabricated TFTs are high gate leakage currents, high threshold voltages, dielectric breakdown, as well as significant high-density SWCNT films negatively impacting the ON/OFF ratio. Etching away excess carbon nanotubes from the active area using photolithography processes and plasma treatment to minimize gate leakage current as well as reducing the SWCNT film density are priority design optimizations.