Organic solar cells (OSC) feature several advantages over “classical” silicon solar cells: low cost, energy effective production, low weight and semi-transparency. This makes them apt for novel applications like, building-integrated photovoltaics (BIPV) with high market potential. However, both the efficiency and the long-term stability must be enhanced for OSCs to become profitable. POCAONTAS will develop highly efficient and stable OSCs based on tailored blends of polymers (P) with single wall carbon nanotubes (SWNT), that are ideally suited for OSCs due to their inherent stability, high carrier mobility and the tunability of optical gaps. Up to now, no breakthrough in SWNT based OSC has been achieved due to challenges with the control of SWNT-chirality, -aggregation, orbital energy mismatch and nanoscale sample morphology. Our consortium will address these issues: We will synthesize functional polymers that (i) allow for a tailored selection of SWNT chiralities, and (ii) match the SWNT energy levels to polymers for maximization of efficiency. The introduction of SWNT-P exchange protocols enables us to optimize (i) and (ii) with different polymers, avoiding compromises in performance. We will obtain optimized donor-acceptor blends, in which the SWNTs are light antenna and charge transporter. We unify leading European groups in time- (down to 10 fs) and spatially (down to 10 nm) resolved spectroscopies providing unique insights into SWNT-P interactions at the molecular level. Experts in multi-scale quantum chemical modeling will develop greater predictive power of charge transport. FLEXINK, a startup in optoelectronics materials, will provide tailored polymers. KONARKA, world leader in commercial OSCs, will build and test solar cells using our blends. Both full partners can directly exploit the project’s outcome to strengthen their market position. Three associated industrial partners provide industry internships for each ESR maximizing their career perspectives.