Radical-Mediated Creation of Fluorescent Defects in Carbon Nanotubes

Abstract

The fluorescent defects in carbon nanotubes have been demonstrated to give exceeding optical properties such as room temperature single photon emissions at telecom wavelengths. A handful of methods for creating these defects have been invented in the past 13 years and provides practical guidelines for obtaining desired functional groups. However, most reactions are performed in the aqueous solution, and the transfer of the single-wall carbon nanotubes (SWCNTs) from aqueous to organic solvents are usually challenging. This gives barriers for applications that require SWCNTs to be dissolved in an organic solvent. Here, we introduce controlled creations of three different fluorescent defects in carbon nanotube hosts in organic solvents using a single radical initiator. We achieved selective creations of benzyl, phenyl, and benzoyloxy defects by controlling the reaction conditions such as dissolved oxygen concentration, reaction temperature, solvents, and addition of radical scavengers. It is worth noting that the both radical initiator and solvent can provide functional groups at the defect sites through radical reaction. We believe that this method will serve as a practical platform for designing new fluorescent defects in the organic phase.