Increase of open circuit voltage of polymer bulk heterojunction solar cell by functionalized single walled carbon nanotubes

We report on an improvement of the open circuit voltage over 0.8 V, together with decent fill factor and large short circuit current, through the incorporation of ester-functionalized single wall carbon nanotubes in a poly(3-hexylthiophene): 1-(3-methoxycarbonyl) propyl-1-phenyl[6,6]C61 bulk heterojunction solar cell. The technique may open new margins for an extra efficiency enhancement through increase of the open circuit voltage using state of the art highly crystalline low band gap bulk heterojunction polymer solar cells.