1. KAUST Solar Center (KSC), and Division of Physical Sciences and Engineering; King Abdullah University of Science and Technology (KAUST); Thuwal 23955-6900 Saudi Arabia
2. Department of Materials Science and Engineering; Stanford University; Stanford 94305 CA USA
3. Department of Chemistry; University of Kentucky; Lexington 40506 KY USA
4. Department of Chemistry; University of Southern California; Los Angeles 90089 CA USA
5. Dresden Integrated Center for Applied Physics and Photonic Materials and Institute for Applied Physics; Technische Universität Dresden; George-Bähr-Str. 1 01069 Dresden Germany