Highly polarized absorption and photoluminescence of stretch-aligned single-wall carbon nanotubes dispersed in gelatin films

Substantial alignment of isolated individual single-wall carbon nanotubes (SWNTs) has been achieved by mechanically stretching gelatin films filled with homogeneously dispersed SWNTs. Highly polarized absorption and photoluminescence are observed that are attributed to interband optical transitions in SWNTs. Sharp and well-resolved spectral peaks comparable to those for an SWNT micelle suspension confirm good isolation of the tubes in dried films. Gelatin’s remarkable features such as miscibility with SWNT micelles, protective colloid, film-forming ability, and stretchability play important roles in the success. The realization of highly aligned and luminescent SWNT thin films should contribute to the development of SWNTs as novel optoelectronic materials.