Self-Assembled Microhoneycomb Network of Single-Walled Carbon Nanotubes for Solar Cells
journal contributionposted on 16.12.2015, 23:15 by Kehang Cui, Takaaki Chiba, Shuichiro Omiya, Theerapol Thurakitseree, Pei Zhao, Shunjiro Fujii, Hiromichi Kataura, Erik Einarsson, Shohei Chiashi, Shigeo Maruyama
We propose a water vapor treatment to direct the formation of single-walled carbon nanotubes (SWNTs) into a self-assembled microhoneycomb network (μ-HN) for the application to SWNT-Si solar cells. The μ-HN consists of vertical aggregated SWNT walls and a buckypaper bottom. This hierarchical structure exhibits lower sheet resistance and higher optical transmittance compared with buckypaper. The pristine μ-HN SWNT-Si solar cell shows a record-high fill factor of 72% as well as a power conversion efficiency (PCE) of 6% without optimizing the diameter or height of the vertically aligned SWNTs. The PCE remains stable for weeks under ambient condition, and a PCE exceeding 10% is achieved in the dry state after dilute nitric acid treatment.