1. Department of Materials Science and Engineering, Penn State University, University Park, Pennsylvania 16801, United States
2. Bio-inspired Materials and Devices Laboratory (BMDL), Center for Energy Harvesting Materials and Systems (CEHMS), Virginia Tech, Blacksburg, Virginia 24061, United States
3. Electronic Materials Research Center, Korea Institute of Science and Technology, 39-1 Hawolgok-Dong, Sungbuk-gu, Seoul 136-791, South Korea
4. KIST-SKKU Carbon-Neutral Research Center, Sungkyunkwan University (SKKU), Suwon 16419, Republic of Korea
5. Department of Physics and Astronomy, Indiana University South Bend, South Bend, Indiana 46634, United States
6. KICP and Department of Physics, Enrico Fermi Institute, University of Chicago, Chicago, Illinois 60637, United States
7. Donostia International Physics Center (DIPC), Paseo Manuel Lardizabal 4, 20018 Donostia-San Sebastian, Spain