1. Department of Chemical Engineering & Materials, University of California, Santa Barbara, California 93106, United States
2. Center for Polymers and Organic Solids, Departments of Chemistry & Biochemistry and Materials, University of California, Santa Barbara, California 93106, United States
3. Department
of Physics, University of California, Berkeley, California 94720, United States
4. Molecular
Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
5. Kavli Energy
NanoSciences
Institute at Berkeley, Berkeley, California United States