1. Centre
for Research on Adaptive Nanostructures and Nanodevices (CRANN) and
Advanced Materials and BioEngineering Research (AMBER), Trinity College Dublin, Dublin 2, Ireland
2. Department
of Electrical Engineering and Computer Science, University of Siegen, Hölderlinstraße 3, 57076 Siegen, Germany
3. School
of Chemistry, Trinity College Dublin, Dublin 2, Ireland
4. Faculty
of Physics, University of Vienna, Boltzmanngasse 5, A-1090 Vienna, Austria