Understanding Current Changes of Back‐Contact Silicon Solar Cells After a Separation Step

Back‐contact (BC) solar cells, which avoid front‐side metallization losses, represent one of the most promising high‐efficiency photovoltaic architectures, with recent hybrid interdigitated back‐contact devices achieving efficiencies up to 28.29%. Although cell cutting is commonly required in module fabrication to control series resistance, the impact of cutting on BC cells has not been systematically investigated. In this work, we report the systematic study of cutting‐induced performance changes in heterojunction back‐contact (HBC) cells and identify a pronounced loss in short‐circuit current density ( J sc ). Combined experiments and Quokka simulations reveal that the BC architecture fundamentally alters carrier transport and passivation behavior, resulting in exceptionally low tolerance to edge recombination. Consequently, J sc degradation intensifies with an increasing number of cut edges. To address this limitation, we adopted self‐assembled monolayer to achieve edge passivation, which increased the absolute efficiency of HBC by 0.8%–1%. These findings establish the underlying physics of cutting‐induced losses in HBC cells and provide a viable process strategy for efficient BC modules, offering direct relevance for industrial deployment.