1. Materials Science and Engineering Physical Science and Engineering Division King Abdullah University of Science and Technology (KAUST) Thuwal 23955‐6900 Saudi Arabia
2. School of Chemical Engineering and Light Industry Guangdong University of Technology (GDUT) Guangzhou 510006 China
3. Physics Department Faculty of Science King Abdulaziz University Jeddah 21589 Saudi Arabia
4. Center of Nanotechnology King Abdulaziz University Jeddah 21589 Saudi Arabia