In our work we develop new methods to scale-up aqueous separation techniques for the fabrication of inks and large area thin films of carbon nanotubes. This allows us to study the interaction of polymer-free single chirality and polychiral mixtures of nanotubes with acceptors such as C₆₀ for energy applications such as solar cells. We are using transfer matrix calculations to theoretically calculate the optimal layer thicknesses within a nanotube solar cell and show that light absorption can be tailored to nanotube’s primary (S₁₁) or secondary (S₂₂) absorption peak, or a combination thereof. Upon using large diameter, (9,8), and mixtures of carbon nanotubes we then investigate the required net driving energy for SWCNT exciton dissociation onto C₆₀ and establish a family of (n,m) species that can efficiently be utilized in polymer-free SWCNT:C₆₀solar cells. Possible strategies to extend this diameter limit are discussed.

[1] M. Pfohl, K. Glaser, A. Graf, A. Mertens, D. Tune, T. Puerckhauer, A. Alam, L. Wei, Y. Chen, J. Zaumseil, A. Colsmann, R. Krupke, B. S.Flavel, Probing the Diameter Limit of Single Walled Carbon Nanotubes in SWCNT:Fullerene Solar Cells, Advanced Energy Materials, 6, 2016, 16008900 . DOI: 10.1002/aenm.201600890

[2] M. Pfohl, K. Glaser, J. Ludwig, D. D. Tune, S. Dehm, C. Kayser, A. Colsmann, R. Krupke, B. S. Flavel, Performance Enhancement of Polymer-Free Carbon Nanotube Solar Cells via Transfer Matrix Modeling, Advanced Energy Materials, 6 2016 1501345. DOI: 10.1002/aemn.201501345.