Enhancing n‐Type TOPCon Solar Cell Performance Through Nafion Edge Passivation to Mitigate Degradation

The long‐term performance and efficiency of n‐type TOPCon (tunnel oxide passivated contact) solar cells are often compromised by degradation mechanisms, particularly edge recombination and environmental factors. While various passivation strategies exist, their practical application can be limited. This work introduces and systematically evaluates a scalable, low‐temperature Nafionedge passivation method, uniquely demonstrating its superiority not only to untreated cells but also to conventional nitrogen treatment and a sequential nitrogen‐Nafion combination. The study compared untreated cells to those treated with nitrogen, Nafion, and both, revealing that the standalone Nafion treatment is the most effective approach for performance enhancement and degradation mitigation. Critically, Nafion‐treated cells achieved the highest performance, with a fill factor (FF) of 78.61% and efficiency of 21.84%. These cells also exhibited exceptional long‐term stability, showing only a 6.77% reduction in performance, significantly outperforming untreated cells (12.46% reduction) and, notably, the cells treated with the combined nitrogen‐Nafion process (10.66% reduction). This finding suggests that a single‐step Nafion application is more effective than a multistep process involving high‐temperature annealing. PVsyst simulations further validated these improvements in stability and efficiency, underscoring Nafion edge passivation as a powerful and practical strategy for optimizing the design and maintenance of durable photovoltaic systems.