1. Department of Physics, Chemistry and Biology; Biomolecular and Organic Electronics; Linköping University; Linköping 58183 Sweden
2. Center for Physical Sciences and Technology; Savanoriu˛ pr. 231 Vilnius LT-02300 Lithuania
3. Department of Physics, Chemistry and Biology; Complex Materials and Devices; Linköping University; Linköping 58183 Sweden