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We have fabricated prototypical Al/single-wall carbon nanotube (SWNT)-polymer/indium tin oxide thin-film devices that exhibit promising photoconductive and photovoltaic responses in a broad spectral range, typically from 300 to 1600 nm. This achievement was made possible by finely dispersed SWNT powders in polymer matrices such as poly-phenylene-vinylene and poly-thiophene. These devices utilize (i) the intrinsic near-infrared light harvesting properties of semiconducting SWNTs, (ii) the electronic transport properties of both semiconducting and metallic SWNTs in combination with those of the polymer matrices, and (iii) probably charge/energy transfer processes between SWNTs and the polymers. By selecting different sources of SWNTs and polymers, we have shown that the optoelectronic properties of these devices are potentially tunable. To support our investigation, several techniques including spectrally resolved photoconductivity, optical absorption, and photoluminescence spectroscopy were utilized. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]