New screen-printing method slashes silver use in TOPCon solar designs

The University of New South Wales, based in Sydney, and Changzhou Fusion New Materials, a China-based PV materials company, have developed a silver-lean screen-printing method for TOPCon solar cells. The process includes printing silver dashes to contact the silicon surface, followed by floating fingers and busbars using silver-lean pastes. According to the researchers, this approach has reduced rear-side silver consumption by 85% with only a 0.1% efficiency drop in 25%-efficient cells. When applied to both surfaces, silver usage was as low as 2 mg/W. A negative interaction between silver dashes and aluminum fingers during co-firing was observed and requires further optimization. The University of New South Wales has stated that with improved patterning and printing, this method could match the efficiency of current industrial TOPCon designs while lowering material costs.