1. Institute for Solar Energy Systems, Guangdong Provincial Key Laboratory of Photovoltaic Technology, School of Physics, Sun Yat-Sen University, 510006 Guangzhou, China
2. IEK-5 Photovoltaik, Forschungszentrum Jülich, 52425 Jülich, Germany
3. International Solar Energy Research Center—ISC Konstanz, 78467 Konstanz, Germany
4. IEK-2 Microstructure and Properties of Materials, Forschungszentrum Jülich, 52425 Jülich, Germany