ABSTRACT: Strong transparent multiwall carbon nanotube (t-CNT) sheets [ 203511]. We prove here that t-CNT plays an essential role as three-dimensional (3-D) hole-collecting network with extended interface connectivity to photoactive layer of bulk heterojunction OPV. Although, the sheet resistance of as-prepared t-CNT is higher than that of ITO, we demonstrate that combining 3-D t-CNT network with planar ITO leads to twice increased photocurrent. So even in unoptimized OPV, a short circuit current density of 11 mA/cm 2 is obtained, which is a significant increase, compared to only $5.5 mA/cm 2 of photocurrent in sole ITO device, and in sole t-CNT case, increasing the overall efficiency to $2%. This enhancement is due to a combined effect of an enhanced hole collection by 3-D t-CNT and improved transport via planar ITO part. Flexible OPVs on plastic substrates also show enhanced performance with hybrid t-CNT–ITO anodes. Published by Elsevier B.V.
Solar Energy Materials & Solar Cells Science Appl. Phys. Lett. 01/2007; 91(87):416-419.