1. Department of Chemistry, Ångström Laboratories, Uppsala University, Box 523, SE75120 Uppsala, Sweden
2. Department of Electrical Engineering, Uppsala University, Box 534, SE75121 Uppsala, Sweden
3. Department of Materials Science and Engineering, Uppsala University, Box 534, SE75120 Uppsala, Sweden
4. Department of Chemistry, Qena Faculty of Science, South Valley University, 83523 Qena, Egypt