Aligned carbon nanotube webs as a replacement for indium tin oxide in organic solar cells

► Drawable carbon nanotube webs were used as an anode in bulk heterojunction cells. ► One and two layers of carbon nanotube webs were compared. ► A thick active layer of ~ 530 nm was needed to avoid shunting through nanotubes. ► Two layers of web gave the better efficiency of 1.6%. ► Flexible devices on Mylar were demonstrated with 1.2% efficiency.