Selective deposition of semiconducting single-walled carbon nanotubes onto amino-silane modified indium tin-oxide surface for the development of poly(3-hexylthiophene)/carbon-nanotube photovoltaic heterojunctions

A method is described to obtain separation of single-walled carbon nanotubes (SWCNTs) on an indium tin-oxide (ITO) substrate by modifying the conducting surface of ITO with amino-silane functional groups. Scanning electron microscopy confirmed that the amino-silane functionalization of the substrate is a critical parameter for the immobilization of separated nanotubes. In particular spin coating the SWCNT solution onto the amino-silane modified ITO surface results in a lower nanotube density with respect to the reference sample obtained on pure ITO together with the immobilization of semiconducting carbon nanotubes onto the substrate. The possibility of using these SWCNT thin films to obtain polymer/nanotube heterojunctions for the development of organic solar cells is considered.