Having collaborated for just over two years, Kaneka and imec are to jointly present a paper at the 21st International Photovoltaic Science and Engineering Conference (PVSEC-21), which is currently being held in Fukuoka City, Japan. The paper demonstrates for the first time a heterojunction cell with a copper-electroplated top-grid electrode. Fabricated on a 6-inch silicon substrate, the electroplated copper contact produced a conversion efficiency of more than 21%. The work was carried out and confirmed at imec in collaboration with Kaneka engineers.
Mainstream PV manufacturers have looked to copper contacts to overcome silver screen-printing hurdles of lowering resistivity and thinning the metal line to increase surface area and boost cell efficiency above the 20% threshold.
However, many regard copper-electroplating as a higher-cost process requiring significant changes to equipment and process flows.
According to imec, which has long been involved in copper technologies for the semiconductor industry, its copper-electroplating technique not only achieves higher efficiencies but also reduces fabrication costs.
Kaneka’s Photovoltaics European Laboratory is located at the imec campus in Leuven, Belgium, which is tasked with both thin-film and next-generation heterojunction cell development.
However, recently Kaneka stopped production of amorphous silicon thin-film modules.