1. Laboratory of Organic Electronics, Department of Science and Technology, Linköping University, NorrköpingSE-601 74, Sweden
2. Wallenberg Wood Science Center, Linköping University, NorrköpingSE-601 74, Sweden
3. Institute of Electronic Structure and Laser, Foundation for Research and Technology─Hellas, Heraklion Crete71110, Greece
4. NCD-SWEET Beamline, ALBA Synchrotron Light Source, Carrer de la Llum 2-26, Cerdanyola del Vallès08290, Spain