Single-wall carbon nanotubes (SWCNT) have attracted great interest for applications in a variety of research areas, including electronics and functional materials. However, a good dispersion of these materials in polymer matrices is a demanding factor in order to obtain more homogeneous and less bundled films for constructing optoelectronic and electrochemical devices. In this report we describe a covalent modification with thiophene groups located at the edges and at defects in SWCNT to modify the interaction with the polymer matrix aiming at its application in solar cells. The modified SWCNT and its composites with poly(3-octylthiophene) were characterized by Raman, infrared, UV-vis, and luminescence spectroscopies and cyclic voltammetry. The best bulk heterojunction solar cell was obtained using 5 wt % of the modified carbon nanotube (SWCNT-THIOP) and shows open circuit voltage (VOC), short-circuit current (I sc ), and efficiency (η) of 0.75 V, 9.5 µA cm -2 , 0.184%, respectively.

We report the preparation of photovoltaic devices using modified single wall carbon nanotubes, SWNTs. Devices are produced stacking on top of fluorine‐doped tin‐oxide, an electrochemically deposited polybithiophene layer, a layer of SWNT blended with poly(3‐octylthiophene) and an evaporated top metal contact, Ca/Al or Al. Ca/Al‐top‐electrode devices achieve open‐circuit voltages of 1.81 V and average power conversion efficiency of 1.48% at irradiance of 15.5 W m–2, spectrally distributed following AM1.5. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)