1. Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
2. SLAC National Accelerator Laboratory, Stanford Synchrotron Radiation Lightsource, Menlo Park, California 94025, USA
3. Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, USA
4. PVcomB, Helmholtz-Zentrum Berlin, 12489 Berlin, Germany
5. Department of Chemistry Materials Science and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, USA
6. Physics Department and CSRRI, Illinois Institute of Technology, Chicago, Illinois 60616, USA
7. National Renewable Energy Laboratory, Golden, Colorado 80401, USA