Advancing Single-Walled Carbon Nanotubes toward Next-Generation Electronic Materials: The Critical Roles of Purity...

Single-walled carbon nanotubes (SWNTs) have garnered significant attention due to their unique size- and structure-dependent properties, making them highly promising for a wide range of applications. Among these properties, their exceptional electrical conductivity positions them as potential alternatives to traditional metal conductors. However, despite the outstanding conductivity of individual SWNTs (10⁵-10⁸ S m^-1), bulk SWNT materials do not exhibit a simple additive scaling of conductivity (<10⁵ S m^-1) due to various limiting factors. This discrepancy arises from the challenges associated with solution processing and purity, which are critical for translating the intrinsic conductivity of individual nanotubes into macroscopic assemblies. This review provides an overview of recent advancements in methodologies aimed at improving both the solution processability and electrical performance of bulk SWNT materials, with a particular emphasis on purification and sorting strategies. Additionally, we discuss the dual role of dispersants used during SWNT sorting, which facilitate tube de-bundling but often remain on the nanotube surface as insulating residues, necessitating further processing to fully restore electrical performance. By consolidating recent insights, this review identifies the key mechanisms governing conductivity trade-off and proposes practical pathways for translating the intrinsic performance of SWNTs into highly conductive bulk assemblies for future electronic applications.