1. Photonics
and Optoelectronics Group, Department of Physics and Center for NanoScience
(CeNS), Ludwig-Maximilians-Universität München, Amalienstr.
54, 80799 Munich, Germany
2. Nanosystems Initiative Munich (NIM), Schellingstr. 4, 80799 Munich, Germany
3. Department
of Chemistry, Ludwig-Maximilians-Universität München, Butenandtstr.
5-13 (E), 81377 Munich, Germany
4. General Electric (GE) Global Research, Freisinger Landstr. 50, 85748 Garching bei München, Germany