Keywords:carbon nanotubes, color centers, chemical reaction
Color centers in single-walled carbon nanotubes are of interest because of their single-photon emission at room temperature in the telecom range [1, 2], but the lack of vapor-phase reaction route for forming the color centers hinders the use of the excellent optical properties of air-suspended carbon nanotubes. We herein demonstrate the functionalization of air-suspended carbon nanotubes using iodobenzene as a precursor. We rationally design the chemical reaction procedure without compromising the suspended structure. Formed phenyl group serves as a color center and exhibits localized exciton emission peaks E11* and E11*- in addition to the free exciton emission peak E11. We characterize representative 12 chiralities to reveal the diameter-dependent reactivity and optical property of the color centers. We quantitatively describe the reactivity, where a strain of nanotube curvature promotes the reaction. The trapping potential of E11* and E11*- excitons also shows the diameter dependence, which we discuss in the presentation. These findings should lead to further development of quantum photon sources that utilize color centers in carbon nanotubes.
This work was supported in part by RIKEN (Special Postdoctoral Researcher Program), MIC (SCOPE 191503001), JSPS (KAKENHI JP15H05760, JP18H05329, JP20K15112, JP20K15137, JP20H02558), and MEXT (Nanotechnology Platform JPMXP09F19UT0077). We thank the Advanced Manufacturing Support Team at RIKEN for technical assistance.