Selective emergence of photoluminescence at telecommunication wavelengths from cyclic perfluoroalkylated carbon nanotubes

Single-walled carbon nanotubes are a promising material for optical applications, but large band gap modulations remain challenging to realize. Here, the authors functionalize single-walled carbon nanotubes using 1,4-diiodooctafluorobutane, achieving a shift in the material's photoluminescence to wavelengths of 1320 nm. Chemical functionalisation of semiconducting single-walled carbon nanotubes (SWNTs) can tune their local band gaps to induce near-infrared (NIR) photoluminescence (PL). However, tuning the PL to telecommunication wavelengths (>1300 nm) remains challenging. The selective emergence of NIR PL at the longest emission wavelength of 1320 nm was successfully achieved in (6,5) SWNTs via cyclic perfluoroalkylation. Chiral separation of the functionalised SWNTs showed that this functionalisation was also effective in SWNTs with five different chiral angles. The local band gap modulation mechanism was also studied using density functional theory calculations, which suggested the effects of the addenda and addition positions on the emergence of the longest-wavelength PL. These findings increase our understanding of the functionalised SWNT structure and methods for controlling the local band gap, which will contribute to the development and application of NIR light-emitting materials with widely extended emission and excitation wavelengths.

Automated summary

The authors achieved a shift in the photoluminescence wavelength of single-walled carbon nanotubes to 1320 nm by functionalizing them with 1,4-diiodooctafluorobutane. This finding contributes to the development and application of near-infrared light-emitting materials.