1. Advanced Passivation Technology Lab College of Physics Science and Technology Hebei University Baoding 071002 China
2. State Key Laboratory of Photovoltaic Materials & Technology Yingli Green Energy Holding Co., Ltd. Baoding 071051 China
3. Das Solar Co., Ltd No 43 Bailing South Road, Quzhou Green Industry Clustering Zone Quzhou Zhejiang 324022 China