Imec and Kaneka research copper for silicon solar cells
The two entities showed the solar cells at the International Photovoltaic Science and Engineering Conference this week in Fukuoka, Japan.
The silver-free heterojunction silicon solar cells resulted from applying copper electroplating technology, which was developed by Kaneka based on imec’s existing copper electroplating technology. While silver screen printing is used today for the top grid electrode in heterojunction silicon solar cells the technique is not efficient and the costs are high.
The silver-free formation of top grid electrode with copper-electroplating approach, reported at the conference, is a world first, according to the researchers. Copper-electroplating is an economical and industry-proven process which enables higher efficiencies and reduces fabrication costs.
Imec researchers measured a conversion efficiency of more than 21 percent in 6-inch silicon substrates with an electroplated copper contact grid on top of the transparent conductive oxide layer. The conversion results were based on imec’s copper electroplating knowhow and obtained in Kaneka’s Photovoltaics European Laboratory located at the imec campus in Leuven.