1. School
of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332-0400, United States
2. Center
for Organic Photonics and Electronics, Georgia Institute of Technology, Atlanta, Georgia 30332-0400, United States
3. Solar & Photovoltaics Engineering Research Center, Division of Physical Science and Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Kingdom of Saudi Arabia
4. School
of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0250, United States