Degradation Mechanism of TOPCon Solar Cells in an Ambient Acid Environment.

n-Type tunnel oxide passivated contact (TOPCon) solar cells are expected to dominate the global photovoltaic market in the next decade, primarily owing to their rapidly increasing power conversion efficiency (PCE). However, acids generated from encapsulant hydrolysis under damp-heat (DH) conditions significantly impair the reliability of TOPCon solar cells. This study evaluated the degradation behavior of TOPCon solar cells under an accelerated test in an ambient acid environment.