1. Department of Electrical Engineering, Stanford University, Stanford, California 94305, United States
2. Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, United States
3. Department of Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
4. Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
5. Department of Physics, India Institute of Science, Bangalore 560012, India
6. Precourt Institute for Energy, Stanford University, Stanford, California 94305, United States