1. Natubhai V. Patel College of Pure & Applied Sciences, The C .V. M. University, Vallabh Vidyanagar-388 120, Anand, Gujarat, India
2. Department of Physics, Sardar Patel University, Vallabh Vidyanagar-388 120, Anand, Gujarat, India
3. C. L. Patel Institute of Studies and research in renewable Energy, The C. V. M. University, Vallabh Vidyanagar-388 120, Anand, Gujarat, India