BYD Patent for Silver-Carbon Paste Aims to Cut Resistance in Heterojunction Solar Cells

BYD has secured a Chinese patent for a silver-carbon paste designed for heterojunction (HJT) solar cells. The paste uses carbon nanotubes with defects to improve silver adhesion and filling, which reduces contact and series resistance. This addresses a common problem where adding carbon materials to reduce silver usage ends up increasing resistance and lowering cell efficiency. The invention could make HJT cells more cost-effective by potentially cutting the amount of silver needed while maintaining or improving conductivity. Since silver is a major cost driver in solar cell production, this material innovation might help HJT compete better against TOPCon and other cell technologies. While the patent is a promising step, it remains to be seen how it performs in large-scale manufacturing. If the paste delivers on its claims, it could support wider adoption of high-efficiency heterojunction modules and contribute to lower per-watt costs in solar installations.