imec unveils world's first silver free heterojunction silicon solar cells
Nanoelectronics research centre, imec, has developed the world's first silver free heterojunction silicon solar cells with copper electroplating, paving the way for high efficiency and reduced fabrication costs.
Working in conjunction with Kaneka, a photovoltaics organisation, imec used new copper electroplating technology to achieve a conversion efficiency of more than 21% in 6in silicon substrates with an electroplated copper contact grid on top of the transparent conductive oxide layer.
Currently, silver screen printing is used when developing the top grid electrode in heterojunction silicon solar cells, but the difficulty of lowering resistivity and thinning the metal line in silver screen printing makes it difficult to achieve high efficiency and low cost. In the new silver free technique, the screen printed silver is replaced by electroplated copper – a more economical process that enables much higher efficiency.
imec made the announcement at the 21st International Photovoltaic Science and Engineering Conference in Fukuoka, Japan.
