Enrichment of solution-processable single-walled carbon nanotubes for flexible nanoelectronics

Abstract

Here we fabricate solution-processable single-walled carbon nanotubes that feature enhanced dispersion in solvents while still affording excellent structural integrity, which is examined by adopting both the microscopic (scanning electron microscopy) and spectroscopic (Raman spectroscopy) characterization techniques. The controlled functionalization is key to producing the electronic grade carbon nanotubes that exhibit the G-to-D peak ratio easily exceeding 10 when deposited as a thin-film by spin coating. A comparative study is conducted to further investigate the effect of the deposition method (spin coating versus drop casting), the chemical treatment (functionalization), and the substrate (rigid substrates such as SiO2 or glass, and flexible substrates such as polyimide) on the structural properties of carbon nanotubes. Additionally, a low-cost inkjet printing method enables us to study the current-voltage characteristics of carbon nanotube thin-films of varying channel lengths, and the measured electrical resistivity values approach those of moderately doped semiconducting materials (in the range of 10−3 Ωm). This study suggests that upon the mild acid treatment, the single-walled carbon nanotubes possess the potential to advance flexible nanoelectronics.