1. Physics
of Energy, Department of Physics and Astronomy, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
2. Energy
and Semiconductor Research Laboratory, Institute of Physics, Carl von Ossietzky University of Oldenburg, Carl-von-Ossietzky-Strasse 9-11, 26129 Oldenburg, Germany
3. Liquid Crystals R&D Chemistry, Merck KGaA, Frankfurter Strasse 250, 64293 Darmstadt, Germany