1. Department of Physics and Astronomy, University of Nebraska-Lincoln, Lincoln, NE 68588, USA
2. Department of Physics, University of Central Florida, Orlando, FL 32816, USA
3. Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL 32306, USA
4. Department of Chemistry, University of Nebraska-Lincoln, Lincoln, NE, 68588, USA
5. Department of Physics, Indiana University-Purdue University Indianapolis, Indianapolis, Indiana 46202, USA
6. Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
7. Nebraska Center for Materials and Nanoscience, University of Nebraska-Lincoln, Lincoln, NE 68588, USA