1Center for 2-Dimensional and Layered Materials, The Pennsylvania State University, University Park, PA, 16802, USA
2Department of Physics, The Pennsylvania State University, University Park, PA 16802, USA
3Department of Materials Sciences and Engineering, The Pennsylvania State University, University Park, PA16802, USA
4Department of Chemistry, The Pennsylvania State University University Park, PA 16802 USA
5Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
6Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
7Geballe Laboratory for Advanced Materials, Stanford University, Stanford, CA 94305, USA
8Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
9Department of Chemical and Petroleum Engineering, University of Pittsburgh, Pittsburgh, PA, 15213, USA
10Departments of Physics and Electrical Engineering, Columbia University, New York, NY 10027, USA
11Institut für Experimentelle und Angewandte Physik, Universität Regensburg, 93040 Regensburg, Germany
12Department of Physics and Astronomy, The University of Kansas, Lawrence, KS 66045, USA
13Department of Materials Science and Engineering, the University of Virginia, Charlottesville, VA 22904, USA
14Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305 USA
15SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
16Department of Physics, University of Arizona, Tucson, AZ, 85721 USA
17Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA 19104, USA.
18Department of Electrical and Computer Engineering, Lehigh University, Bethlehem, PA 18015, USA
19Department of Chemistry and Institute of Molecular Engineering, University of Chicago, Chicago, IL 60637, USA
20Department of Electrical and Computer Engineering Rutgers University, Piscataway, NJ 08854, USA
21Department of Materials Science and Engineering, Rutgers University, Piscataway, NJ 08854, USA
22Electrical Engineering and Computer Sciences, University of California at Berkeley, Berkeley, CA 94720, USA
23Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
24Department of Chemistry, Northwestern University, Evanston, IL 60208, USA
25Department of Materials Science and Engineering Northwestern University Evanston, IL 60208 (USA)
26Center for Atomically Thin Multifunctional Coatings (ATOMIC), The Pennsylvania State University, University Park, PA 16802, USA
