Electrical Analysis of Non-Destructive-Cut HPBC Solar Cells via Crack Driving Index

Non-destructive cutting (NDC) is promising for fabricating high-efficiency half-cut solar cells by minimizing thermal and mechanical damage during cell cutting. Here, a dual-laser NDC process, comprising an infrared (IR) laser for pre-cut formation and a thermal laser for crack propagation, was applied to hybrid passivated back contact solar cells. Accordingly, the effects of scan speed, IR laser-induced pre-cut depth, and thermal laser power were systematically investigated at scan speeds of 300, 400, and 500 mm/s. Furthermore, stable process windows for cleaving were identified, within which fill factor and maximum power were evaluated. Despite differences in absolute laser power and scan speed, the highest electrical performance was consistently achieved at an intermediate pre-cut depth combined with the maximum thermal laser power available within each process window. To elucidate this behavior, a crack-driving index (ψ) was introduced to consider the coupled effects of thermal driving and crack guidance. The ψ-based analysis reveals that higher scan speeds enhance process sensitivity, highlighting a trade-off between peak performance and process robustness.