Assessing the LECO Process: Its Impact on TOPCon Solar Cell and Module Reliability

This study investigates the impact of the laser-enhanced contact optimization (LECO) process on the long-term reliability of tunnel-oxide passivated contact (TOPCon) solar cells. TOPCon technology, which became the dominant photovoltaic (PV) technology in 2024, faces challenges related to moisture ingress and metallization stability. The research compares the performance of LECO and non-LECO TOPCon cells encapsulated with ethylene vinyl acetate (EVA) and polyolefins (PO) under damp heat (DH) and potential-induced degradation (PID) tests. Initial results indicate that while PO encapsulants mitigate PID, they do not prevent degradation under extended DH testing. The study highlights the necessity of tailored solutions to address various degradation mechanisms and emphasizes the importance of further testing LECO-processed cells to ensure the long-term success of TOPCon technology.