1. Heliatek consolidates its technology leadership by establishing a new world record for organic solar technology with a cell efficiency of 12% (Heliatek, 2013), http://www.heliatek.com/en/press/press-releases/details/heliatek-consolidates-its-technology-leadership-by-establishing-a-new-world-record-for-organic-solar-technology-with-a-cell-effi . Accessed 28 August 2015
2. M. Jorgensen, K. Norrman, F.C. Krebs, Sol. Energy Mater. Sol. Cells 92, 686–714 (2008)
3. V. Turkovic, S. Engmann, D.A.M. Egbe, M. Himmerlich, S. Krischok, G. Gobsch, H. Hoppe, Sol. Energy Mater. Sol. Cells, Part B 120, 654–668 (2014)
4. F.C. Krebs, Sol. Energy Mater. Sol. Cells 92, 715–726 (2008)
5. M.D. Alexander, C.E. Specker, D.S. Dudis, in Reactive Intermediates in Organic and Biological Electrochemistry, ed. by D.G. Peters, H.J. Schafer, M.S. Workentin, J. Yoshida (The Electrochemical Society, Pennington, 2001), pp. 164–167