1. Department of Chemistry-Ångström Laboratory; Uppsala University; Box 538 SE-751 21 Uppsala Sweden
2. The Organic Photonics and Electronics Group; Department of Physics; Umeå University; SE-901 87 Umeå Sweden
3. LunaLEC AB; Tvistevägen 47 SE-907 19 Umeå Sweden
4. Department of Engineering Sciences; Uppsala University; Box 534 SE-751 21 Uppsala Sweden