Oxygen defects in single-wall carbon nanotubes for near-infrared light emitters

A new peak with an increased intensity was observed in the photoluminescence (PL) spectra of single-walled carbon nanotubes (SWCNTs), exposed to UV irradiation in the presence of sodium hypochlorite. It was concluded on the basis of the spectroscopic data that the new PL peak is associated with oxygen defects in the SWCNT structure. The impact of environmental acidity on the optical properties of oxygen-doped SWCNTs (O-SWNTs) was investigated. An increased sensitivity of the new PL peak to the pH of the medium was observed. It was concluded that the usage of a pH-neutral medium is of crucial importance for the creation of IR light sources based on O-SWNTs.