1. Soft Matter Physics and Optoelectronics, Institute of Physics and Astronomy, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14476 Potsdam-Golm, Germany
2. Disordered Semiconductor Optoelectronics, Institute of Physics and Astronomy, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14476 Potsdam-Golm, Germany
3. Institute of Polymer Optoelectronic Materials and Devices, Key Laboratory of Luminescence from Molecular Aggregates of Guangdong Province, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, 510640 Guangzhou, P. R. China