A key progress in introducing single walled carbon nanotubes to photovoltaic devices.

This manuscript describes the use of nitrophenyl-functionalized single-walled carbon nanotubes (NP-SWNT) in organic photovoltaic cells for the first time. We mainly focus on these innovative materials to scout for the replacement or doping of the universal buckminsterfullerene PCBM acceptor in the active layer. An optimization of the functional degree was first conducted for the position of energy bands and then experimentally confirmed. The morphology of the active layer was optimized with the NP-SWNT concentrations up to 20 wt% using additives and processing methods. The key step to avoid short circuits resulting from both high conductivity and high aspect ratio is controlling the NT functional degree and the film morphology. Using a specific functional degree (49 wt%), Organic photovoltaic (OPV) devices exhibit a maximum unprecedented efficiency of 0.13%, at an optimal nanotube loading of around 2 wt%, in BHJ with P3HT as the p-type semiconductor. In a leading precedent, our results constitute important progress for the application of NP-SWNTs in large area solution processed photovoltaic cells and provide insight into the role of structural organization in the device performance. [ABSTRACT FROM AUTHOR]