1. Laboratory for Thin Films and Photovoltaics; Empa-Swiss Federal Laboratories for Materials Science and Technology; Ueberlandstrasse 129 8600 Duebendorf Switzerland
2. Departamento de Física Aplicada; Universidad Autónoma de Madrid; C/ Francisco Tomás y Valiente 7 28049 Madrid Spain
3. Laboratory for Advanced Analytical Technologies; Empa-Swiss Federal Laboratories for Materials Science and Technology; Ueberlandstrasse 129 8600 Duebendorf Switzerland
4. Dept. Structure and Dynamics of Energy Materials; Helmholtz-Zentrum für Materialien und Energie GmbH; Hahn-Meitner-Platz 1 D-14109 Berlin Germany