Aligned Arrays of Semiconducting HiPCO SWCNTs Prepared by Liquid–Liquid Interface Confinement Self-Assembly for Optic–Electronic Applications

In recent years, significant breakthroughs have been achieved in the fabrication of wafer-scale aligned arrays of semiconductor single-wall carbon nanotubes (s-SWCNTs) based on liquid–liquid interfacial self-assembly techniques. High pressure catalytic CO (HiPCO) s-SWCNTs, characterized by small diameters, large band gaps, and multiband optical absorption, hold significant applications in both optical and electronic domains. However, during assembly, HiPCO s-SWCNTs are prone to bending and entanglement, thereby introducing increased complexity into the assembly processes. Here, we evaluate two interfacial assembly methods for their efficacy in aligning HiPCO s-SWCNTs and scrutinize the interfacial phenomena within these two liquid–liquid confinement systems. Utilizing one of these methods, namely, dimension-limited self-alignment, aligned HiPCO s-SWCNT arrays on 4-inch wafers were successfully fabricated. The achieved alignment degree is 10.2°, and the array density of the HiPCO s-SWCNTs reached 300–550 tubes per micrometer. These scientific findings contribute to a more comprehensive understanding of the assembly process of inhomogeneous SWCNTs within confined interfaces and lay an important foundation for the optical and electronic applications of small-diameter HiPCO s-SWCNTs.