Photoluminescence from Encapsulation of Dye Molecules inside Single-Walled carbon nanotubes in Chemical Solvent

Abstract

Photoluminescence (PL) spectrum of single-walled carbon nanotubes (SWNTs) is found around IR range (950~1150nm). Another visible photoluminescence at 515 nm of ruthenium-doped multiwall carbon nanotubes was also reported [2]. Here, we prepared dye@SWNTs by using self-assembly encapsulation method in vacuum. We synthesized and used 1-(2-amino-phenyl) naphthalen-2-ylamine) as a dye. We measured UV/Vis spectroscopy of the dye@SWNTs. As result of UV/Vis of dye@SWNTs, we measured PL spectrum and found Strong visible luminescence at around 400nm at excitation of 216, 265 and 326nm. The observed blue shift of emission peak of encapsulated adduct appear to depend on the energy level of lowest unoccupied molecular orbital (LUMO) of encapsulated dye, consistent with encapsulation by a charge-transfer interaction. We measured PL spectrum as a function of degree of dispersion. PL spectrum intensity was in order, i.e. DMF>Ethanol>H2O, which was equal to the result with the dispersion of carbon nanotube in liquid medium.