1. Physics Department, Altoona College, Pennsylvania State University, Altoona, PA 16601, USA
2. Materials Research Institute, Pennsylvania State University, University Park, PA 16802, USA
3. Department of Physics & Astronomy, University of Louisville, Louisville, KY 40292, USA
4. Physics Department, Pennsylvania State University, University Park, PA 16802, USA
5. Conn Center for Renewable Energy Research, University of Louisville, Louisville, KY 40292, USA