IMPROVING THE PERFORMANCE OF MONOCRYSTALLINE SILICON PERC SOLAR CELLS BY OPTIMIZING FRONT AND REAR METALLIZATION

2022-6
Asav, Hasan
Silicon photovoltaics dominates the solar cell market, accounting for over 95% of the total share. The fabrication process of silicon solar cells includes some crucial steps that have a significant impact on solar cell conversion efficiency. These steps are mainly categorized as surface texturization, diffusion, antireflective coatings, and metallization. Among these crucial steps, metallization is a key step for the reduction and control of the electrical and optical losses of the solar cell. The formation of the electrical contacts is achieved by the metal layers on the front and back surfaces of the solar cell. In this M.Sc. thesis, optimization of the metallization is studied for passivated emitter and rear contact (PERC) solar cells to improve cell performance. Rear side metal contact formation for the PERC solar cell is strongly linked with the laser contact opening (LCO) process which provides a path from the rear surface of the cell to the silicon substrate. Therefore, optimization of LCO is a necessary part of the study to minimize the losses from the rear passivation stack. With this aim, different LCOs are studied and the optimum metal fraction for the rear side is performed on the fabricated PERC solar cells. An average of 6 mV cell Voc increase is gained thanks to these optimizations on the rear side. The metallization process in this study is based on a screen-printing method for the formation of front and rear metal contacts of the PERC solar cell. A GriddlerPro simulation program is utilized to design and simulate the front metal design. Then, the analysis of front metal contacts is done thoroughly. After these optimizations, the fast-firing step is studied and a newly developed recipe is brought to the ODTÜ-GÜNAM laboratories. While new cell designs are rapidly growing, our future goals will include following these new advances closely and employing new metallization schemes that can enhance cell performance.

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Citation Formats
H. Asav, “IMPROVING THE PERFORMANCE OF MONOCRYSTALLINE SILICON PERC SOLAR CELLS BY OPTIMIZING FRONT AND REAR METALLIZATION,” M.S. - Master of Science, Middle East Technical University, 2022.