High Power n-Type Metal-Wrap-through Cells and Modules Using Industrial Processes
| Autor: | Guillevin, N., Heurtault, B., Geerligs, L.J., Van Aken, B.B., Bennett, I.J., Jansen, M.J., Weeber, A.W., Bultman, J., Wang, J., Wang, Z., Zhai, J., Wan, Z., Tian, S., Zhao, W., Hu, Z., Li, G., Yu, B., Xiong, J. |
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| Jazyk: | angličtina |
| Rok vydání: | 2013 |
| Předmět: | |
| DOI: | 10.4229/28theupvsec2013-2bv.2.29 |
| Popis: | 28th European Photovoltaic Solar Energy Conference and Exhibition; 1304-1310 This paper reviews our recent progress in the development of metal wrap through (MWT) cells and modules, produced from n-type Czochralski silicon wafers. The use of n-type silicon as base material allows for high efficiencies: for front emitter-contacted industrial cells, efficiencies above 20% have been reported. N-type MWT (n- MWT) cells produced by industrial process technologies allow even higher efficiency due to reduced front metal coverage. Based on the same industrial technology, the efficiency of the bifacial n-MWT cells exceeds the efficiency of the n-type front-and-rear contact and bifacial “Pasha” technology (n-Pasha) by 0.1-0.2% absolute, with a maximum n- MWT efficiency of 20.1% so far. Additionally, full back-contacting of the MWT cells in a module results in reduced cell to module (CTM) fill factor losses. In a direct 60-cell module performance comparison, the n-MWT module, based on integrated backfoil, produced 3% higher power output than the comparable tabbed front emitter-contacted n-Pasha module. Thanks to reduced resistive losses in copper circuitry on the backfoil compared to traditional tabs, the CTM FF loss of the MWT module was reduced by about 2.2%abs. compared to the tabbed front emitter contact module. A full-size module made using MWT cells of 19.6% average efficiency resulted in a power output close to 280W. Latest results of the development of the n-MWT technology at cell and module level are discussed in this paper, including a recent direct comparison run between n-MWT and n-Pasha cells and results of n-MWT cells from 140μm thin mono-crystalline wafers, with only very slight loss (1% of Isc) for the thin cells. Also reverse characteristics and effects of reverse bias for extended time at cell and module level are reported, where we find a higher tolerance of MWT modules than tabbed front contact modules for hotspots. |
| Databáze: | OpenAIRE |
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