1. Department of Materials Science and Engineering, University of Virginia, 395 McCormick Road, Charlottesville, Virginia 22904-4745, Renewable Energy Materials Research Science and Engineering Center (REMRSEC), Department of Physics, Colorado School of Mines, Golden, Colorado 80401, Thales Research and Technology - France, 91767 Palaiseau Cedex, France, and Instituto de Ciencias Básicas, Universidad Nacional de Cuyo, M5502JMA Mendoza, Argentina