Front-side Metalization By Means Of Flexographic Printing

Flexographic printing is a high-throughput technology which is capable of fine-line printing. The use of a soft and flexible printing plate keeps mechanical stress to silicon wafers during printing low. It is therefore very interesting for the industrial-scale production of seed layers for front-side contact grids on solar cells. Within this work, flexographic printing is applied to silicon solar cells for the first time. We investigate the effect of printing parameters and printing press components on finger width. An average finger width after contact firing of about 44 μm was achieved on wafers of the format 22x60 mm2. Due to reduced shading losses compared to screen printed cells the best flexographically printed cells reached an efficiency gain of 0.7%abs. The highest efficiency was 18.1% and was observed on Cz silicon.