Application of SHJ and TOPCon Shingle Cells in Full Format and Integrated Modules

Shingle technology is attractive due to the absence of ribbons or wires, large active module area, module design flexibility and aesthetically appealing appearance [1]. This work is looking into the application of silicon heterojunction (SHJ) and tunnel oxide passivated contact (TOPCon) shingle cells in small-scale and full-format modules as well as into the effects of overlap minimization and electrically conductive adhesive (ECA) reduction. Stringer tests with subsequent microscopic analysis showed that precision of the laser cutting process is crucial for the correct alignment of metallization and ECA during the interconnection process. Shunting as well as ECA smearing can be caused by the inconsistent distance of the metallization to the cell edge. The variation of the ECA, printing pattern and encapsulation material in small-scale modules demonstrated no difference in performance after production. However, after accelerated thermal cycling (aTC) 50 the modules with SHJ cells showed ∆PMPP = -8.2%rel to +0.4%rel, and TOPCon between -4.5%rel and +0.6%rel, depending on the used encapsulation material. No difference in performance for the modules with reduced ECA amount in comparison with the reference was detected after aTC50. Full-size solar modules with bifacial TOPCon shingles (1/6 G1 format, 20.7% - 21.3% efficiency after the scribe and break laser process) were manufactured with 50% ECA reduction and the optimal materials based on the previous investigation. Peak power values of up to 392.8 Wp and Eta of 19.84% were demonstrated.