Analysis of silver thick-film contact formation on industrial silicon solar cells

The silver thick-film contact is the most widely used front side contact for industrial silicon solar cells [1]. The objective of the presented investigations was to improve the understanding of front side contact formation by varying the contact firing process. We therefore introduced an additional temperature plateau in the cooling zone. The firing process was assessed based on the results of the IV characteristic. Fill factor, series resistance and open circuit voltage were the main values taken into consideration. Additionally we carried out specific contact resistance and Corescan measurements. The performance of the solar cells was characterized by spectrally resolved internal quantum efficiency measurements and thermographic measurements. The results were correlated with the variations of the contact firing and are discussed referring to the different models of the current transport mechanism in thick-film contacts.