How to achieve efficiencies exceeding 22% with multicrystalline n-type silicon solar cells

• Published in: Energy procedia Vol. 124; pp. 777 - 780
• Main Authors: Schindler, Florian, Michl, Bernhard, Krenckel, Patricia, Riepe, Stephan, Benick, Jan, Müller, Ralph, Richter, Armin, Glunz, Stefan W., Schubert, Martin C.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.09.2017
• Subjects: multicrystalline silicon; n-type; TOPCon; TOPCon; n-type; multicrystalline silicon
• ISSN: 1876-6102; 1876-6102
• DOI: 10.1016/j.egypro.2017.09.086

In this contribution, we demonstrate a route for efficiencies exceeding 22% with n-type multicrystalline (mc) silicon solar cells based on the TOPCon cell concept featuring a boron-diffused front side emitter and a full-area passivating rear contact. By applying a “high-performance” (HP) crystallization process with an adapted seed structure in order to obtain an optimized grain boundary area fraction, we reduce recombination losses in the HP mc-Si material to a minimum. We discuss the electrical properties of the optimized n-type HP mc-Si, which features very low material-related efficiency losses of approximately 0.5%abs and, thus, enables an efficiency potential of 22.6% with regard to a cell limit of 23.1% of the TOPCon cell concept adapted for multicrystalline silicon. Results at the device level reveal a record efficiency of 21.9%, which is the highest efficiency reported for a multicrystalline silicon solar cell. Finally, we discuss the deviations between the predicted efficiency potential and the solar cell results.