Improving the efficiency of solar cells is key to reducing the cost of solar power. Now, scientists have developed a new synergistic metallization strategy for tunnel oxide passivated contact (TOPCon) solar cells. The approach achieved a certified power conversion efficiency (PCE) of 26.31%, among the highest reported for this technology.
The new strategy was developed by Professor Ye Jichun's team at the Ningbo Institute of Materials Technology and Engineering (NIMTE) of the Chinese Academy of Sciences (CAS), in collaboration with Soochow University, Zhejiang Gonda Electronic Technology Co., Ltd., and JA Solar Technology Co., Ltd. The relevant findings were published in Matter.
A bottleneck in metallization
Crystalline silicon solar cells currently dominate the photovoltaic industry, with TOPCon technology rapidly capturing market share because of its cost advantages and manufacturing compatibility. By decoupling surface passivation from electrical contact formation, these devices significantly suppress minority-carrier recombination and maintain low contact resistance.
However, conventional metallization processes for fabricating TOPCon solar cells suffer from a trade-off: high-temperature firing of silver-aluminum paste ensures good electrical contact but causes severe passivation degradation and widens gridlines, increasing optical loss—both of which limit efficiency improvements.
