Record low silver use achieved by Fraunhofer ISE in SHJ cells

Scientists at the Fraunhofer Institute for Solar Energy Systems ISE produced silicon heterojunction (SHJ) solar cells with a total silver consumption of 1.4 milligrams per watt peak, about one tenth of the current industrial standard. They reduced silver content in the front-side metallization paste and replaced silver with copper paste on the rear side. An optimized printing process enabled fine electrical contacts. Copper-metallized SHJ solar cells achieved higher efficiency than reference cells with traditional silver contacts. The PV industry accounted for 32 percent of global industrial silver use in 2024, with a sustainable target set at 2 milligrams per watt. Fraunhofer ISE undercut this limit for the first time using screen printing. The project was part of the "HIT" initiative funded by the Federal Ministry of Economics and Climate Protection, with Meyer Burger Germany GmbH as an industrial partner.