1. Institute for Electronics, Department of Information Technology and Electrical Engineering, ETH Zurich, Gloriastrasse 35, CH-8092 Zurich, Switzerland
2. Departamento de Tecnología Fotónica y Bioingeniería & Instituto de Energía Solar, ETSI Telecomunicación, Universidad Politécnica de Madrid, Ciudad Universitaria, ES-20840 Madrid, Spain
3. Institute for Integrated Systems, Department of Information Technology and Electrical Engineering, ETH Zurich, Gloriastrasse 35, CH-8092 Zurich, Switzerland
4. Laboratory for Advanced Analytical Technologies, Empa, Überlandstrasse 129, CH-8600 Dübendorf, Switzerland
5. Department of Physics, Danmarks Tekniske Universitet, Fysikvej, Building 312, 2800 Kgs. Lyngby, Denmark
6. Department of Chemistry, University of Zurich, Winterthurerstrasse 190, CH-8057 Zürich, Switzerland