1. Institute for Semiconductor and Solid State Physics Johannes Kepler University 4040 Linz (Austria);2. Christian Doppler Laboratory for Surface Optics Johannes Kepler University 4040 Linz (Austria);3. Ecole Nationale Superieure de Chimie et de Physique de Bordeaux (ENSCPB) 33607 Pessac Cedex (France);4. Konarka Austria 4040 Linz (Austria);5. Linz Institute for Organic Solar Cells (LIOS) Johannes Kepler University 4040 Linz (Austria)