1. Institute of Photo Electronics Thin Film Devices and Technology of Nankai University
2. Key Laboratory of Photoelectronic Thin Film Devices and Technology
3. Tianjin 300071
4. P. R. China
5. Collaborative Innovation Center of Chemical Science and Engineering (Tianjin)
6. Institute of Semiconductor Materials
7. Hebei University of Technology
8. Tianjin 300130
9. China