Benefits of Pattern Transfer Printing Method for Finger Metallization on Silicon Solar Cells

35th European Photovoltaic Solar Energy Conference and Exhibition; 434-438
In this work, a new technology for the finger metallization on the solar cells, called Pattern Transfer Printing (PTP), is introduced and compared with the screen printing (SP) technology as reference. PTP is a contactless printing technology, which is based on laser induced deposition from a polymer substrate (called tape). Using trench width of 20 μm in the tape, the PTP technology is able to produce ultra-fine-line fingers (< 20 μm) with high aspect ratio (> 0.5). Therefore, the Jsc is increased significantly due to less shadowing and a cell efficiency of 21.8% for a finger cross section of 200 μm². This is a gain of +0.15%abs compared to the SP reference with 35 μm finger opening and simultaneously the silver paste consumption is reduced by 40 mg (-57%). As second reference group double printing with 20 μm finger opening screen is used to achieve a comparable aspect ratio. This results in a similar cell efficiency as for the single print with 35 μm finger opening but with higher paste consumption. The results show, that today the PTP technology is an attractive technology to replace SP for the finger metallization and enable to achieve ultra-fine-line finger printing below 20 μm.