1. a Center for Nanoscale Science and Engineering, and Department of Chemistry , University of California-Riverside , Riverside , California , USA
2. b Advanced Nanofabrication, Imaging and Characterization Core Lab , King Abdullah University of Science and Technology , Thuwal , Saudi Arabia
3. c Department of Physics , Faculty of Science, King Abdulaziz University , Jeddah , Saudi Arabia
4. d Center for Nanoscale Science and Engineering, Department of Chemistry, Department of Chemical and Environmental Engineering , University of California-Riverside, Riverside, California, USA; Department of Physics, King Abdulaziz University , Jeddah , Saudi Arabia