1. Department of Electrical Engineering and Computer Science Massachusetts Institute of Technology Cambridge MA 02139 USA
2. Department of Materials Science and Engineering Sharif University of Technology Tehran 14588 Iran
3. Electrical Engineering Department Sharif University of Technology Tehran 11365-11155 Iran
4. Department of Metallurgical and Materials Engineering Karamanoglu Mehmetbey University Karaman 70100 Turkey
5. Department of Physics Indian Institute of Technology Roorkee Roorkee Uttarakhand 247667 India
6. Institute of Physical Chemistry Polish Academy of Sciences 01-224 Warsaw Poland
7. Department of Solar Energy School of Technology Pandit Deendayal Petroleum University Gandhinagar Gujarat 382007 India