1. Laboratory of Inorganic Chemistry; ETH Zürich; CH-8093 Zürich Switzerland
2. Laboratory for Thin Films and Photovoltaics; Empa-Swiss Federal Laboratories for Materials; CH-8600 Dübendorf Switzerland
3. Department of Theoretical Chemistry; Faculty of Science; Vrije Universiteit Amsterdam; de Boelelaan 1083 1081 HV Amsterdam The Netherlands