1. Center for Organic Photonics and Electronics and School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
2. Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, United States
3. Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
4. Institute for Materials Research (IMO), Hasselt University, Diepenbeek, Belgium
5. Department of Chemisty, Politecnico di Milano, 20133 Milan, Italy
6. King Abdullah University of Science and Technology, Thuwal, Saudi Arabia 23955-6900