1. Department of Chemistry, Photonic and Energy Research Laboratory, The University of Texas Rio Grande Valley, 1201 West University Dr., Edinburg, Texas 78539, United States
2. Department of Physics, The University of Texas at Arlington, Arlington, Texas 76019, United States
3. Department of Chemistry, University of Turin, Turin, TO, Italy
4. Center for Nanotechnology, Department of Mechanical Engineering, The University of Texas Rio Grande Valley, 1201 West University Dr., Edinburg, Texas 78539, United States
5. Department of Chemistry and Biochemistry, University of California, Santa Cruz, Santa Cruz, California 95064, United States