Thinner than a human hair - fine line metallization for next-generation silicon solar cells

The metallization of solar cells with the finest printed lines is one of the most demanding disciplines in the field of printed electronics. Finest lines which are smaller than a quarter of a human hair have to be printed on fragile silicon wafers with high throughput and without interruptions. The aim is to shade as little of the active cell surface as possible and at the same time to ensure high conductivity. Various printing processes can be used for fine-line metallization. In this article, the challenges of solar cell metallization as well as various innovative processes and current results are presented. A special highlight is the metallization of ultra-fine line contacts with a width of only 14 μm.