초록 |
We present the remarkable performance improvement of organic solar cells upon incorporating N- or B-doped carbon nanotubes (CNTs) into the organic semiconductor active layer. A small amount (0.2-5.0 wt%) of doped multi-walled CNTs are added to the bulk-heterojuction of P3HT/PC60BM and PTB7/PC70BM. Unlike undoped metallic multi-walled CNTs, which cause undesired electron-hole recombination, N- or B-doped CNTs uniformly dispersed in the active layer selectively enhance electron or hole transport, respectively, and eventually help carrier collection. Specifically, the incorporation of 1.5 wt% N-doped CNTs results in improved solar cell performance of 8.6%. |