Enrichment of semiconducting single-wall carbon nanotubes by etching energy barrier engineering

Abstract

Horizontally aligned semiconducting single-wall carbon nanotube (s-SWCNT) arrays are ideal candidates for next-generation integrated circuits. However, the mainstream synthesis methods for obtaining s-SWCNTs mainly utilize the differences in structure and chemical reactivity between them and their metallic counterparts. These differences are too small to greatly improve their purity and reproducibility. Here we report an energy engineering strategy to expand the etching energy barrier difference of SWCNTs with different conductivities. In addition to density functional theory calculations on the energy barrier change, hydrogenation of single-wall carbon nanotubes (SWCNTs) by hydrogen plasma treatment and reversible dehydrogenation by annealing were realized experimentally. The structure-dependent hydrogenation and following selective oxidative etching of SWCNTs were demonstrated. As a result, horizontally aligned s-SWCNT arrays with high purity were obtained.