R&D pilot-line production of multi-crystalline Si solar cells with top efficiencies exceeding 19

• Published in: 2011 37th IEEE Photovoltaic Specialists Conference pp. 001919 - 001923
• Main Authors: Engelhart, P., Zimmermann, G., Klenke, C., Wendt, J., Kaden, T., Junghanel, M., Suva, K., Barkenfelt, B., Petter, K., Hermann, S., Schmidt, S., Rychtarik, D., Fischer, M., Muller, J. W., Wawer, P.
• Format: Conference Proceeding
• Language: English
• Published: IEEE 01-06-2011
• Subjects: Passivation; Photovoltaic cells; Photovoltaic systems; Production; Silicon
• DOI: 10.1109/PVSC.2011.6186327
• ISBN: 9781424499663; 1424499666
• ISSN: 0160-8371

In this paper we report on latest results from our pilot production of multi-crystalline (mc) p-type Si cells in the Reiner-Lemoine Research Center at Q-Cells. The cells are double-side contacted and feature a lowly doped emitter, a fineline-printed Ag grid in combination with plating as front metallization and a dielectric passivated rear with local contacts. Using material based on Siemens and upgraded metallurgical grade (100% UMG) feedstock, we achieve stable median cell efficiencies of well above 18 % including the whole brick distribution. Top efficiencies exceeding 19 % (total area) are reached with a standard isotextured front and single anti-reflexion coating. In this work, we show the latest cell optimization progress corresponding to the front metallization process. Furthermore, we report on an independently confirmed cell efficiency of 19.5 % on a large-area multi-crystalline Si solar cell (243 cm 2 ). This efficiency was achieved by implementing next generation process steps. To our knowledge, this result represents the highest energy conversion efficiencies on multi-crystalline Si material achieved so far.