1. Department of Physics, AlbaNova University Center, Stockholm University, 106 91 Stockholm, Sweden
2. Department of Materials and Environmental Chemistry, Stockholm University, Svante Arrhenius väg 16C, 114 18 Stockholm, Sweden
3. Laboratory of Organic Electronics, Department of Science and Technology (ITN), Linköping University, Norrköping, SE-60174 Sweden
4. KBR, Inc., Intelligent Systems Division, NASA Ames Research Center, Moffett Field, California 94035, United States
5. Inorganic Chemistry, University of Wuppertal, Gaußstr. 20, 42119 Wuppertal, Germany
6. Advanced Institute for Materials Research (WPI-AIMR), Tohoku University, Aoba-ku, Sendai 980-8577, Japan