Po-Chuan Yang, Dean of the Global Photovoltaic Research Institute at Risen Energy, highlighted advances in HJT metallization, including lower silver consumption and reduced metallization costs, at the TaiyangNews High-Efficiency Solar Technologies Conference 2025.  (Photo Credit: TaiyangNews)
Technology

Fine-Line Metallization & Silver Reduction In HJT

Narrower fingers, lower silver consumption, and reduced metallization costs are helping improve HJT performance while narrowing the cost gap with mainstream technologies

Shravan Chunduri

  • Risen reduced front-side finger width from 40 μm to 18 μm, improving cell efficiency while lowering silver paste consumption

  • Fine-line metallization is compatible with 110 μm wafers and is supported by a 24-busbar architecture and more than 6,000 ribbon-to-finger contact points to maintain reliability

  • The adoption of silver-coated copper pastes has lowered HJT metallization costs and reduced the technology's sensitivity to rising silver prices

Metallization continues to play a central role in improving the cost competitiveness of heterojunction (HJT) solar cells. Current developments focus on fine grid designs and lower silver consumption while maintaining high electrical performance.

At the TaiyangNews High-Efficiency Solar Technologies Conference 2025, Po-Chuan Yang, Dean of the Global Photovoltaic Research Institute at Risen Energy, discussed advances in fine-line metallization and silver-coated copper adoption, highlighting their role in improving HJT competitiveness. Risen also highlighted major progress in fine-line metallization. According to Yang, front-side finger width has been reduced from 40 μm 3 years ago to 18 μm by the end of 2025. This reduces shading loss and lowers silver paste consumption without compromising conductivity. Optical gains from narrow fingers reduce shading loss, yielding a 1.2% absolute gain in cell efficiency, and material savings enable 15% lower silver paste consumption per Watt, without compromising conductivity. Equally important is the process compatibility with the 110 μm wafer, ensuring mechanical stability during the string. The company tied this reliability to a broader design package that includes a 24-busbar architecture, more than 6,000 ribbon-to-finger contact points, and a reliability strategy built around stress reduction and durability (Watch Presentation here).

Yang also presented the total metallization costs for different cell technologies, considering the times of high silver prices. HJT’s total metallization cost is roughly RMB 0.07/W, comprising about RMB 0.02/W for the ITO target and RMB 0.05/W for silver-copper paste. In comparison, the corresponding cost for TOPCon and BC is higher, at around RMB 0.10/W. This clearly shows that HJT is becoming less sensitive to silver. This is mainly due to the successful adoption of silver-coated copper paste, which significantly reduces silver consumption. However, this solution is not yet a direct drop-in replacement for TOPCon, as the segment is still evaluating its long-term reliability, particularly concerning copper leakage and process compatibility. As a result, this is turning into a competitive advantage for HJT. Beyond the direct savings from lower silver usage, the technology is benefiting from current market dynamics. While the cost of silver was historically one of HJT’s biggest disadvantages, the recent surge in silver prices is shifting the balance in its favor (see Silver-Coated Copper Drives HJT Metallization Roadmap).

The text is an edited excerpt from TaiyangNews’ report on Cell & Module Technology Trends 2026, which can be downloaded for free here.