Carrier Transportation at Novel Silver Paste Contact

When our novel Ag paste is used, the high solar cell performance is obtained. A thick SiON layer is formed between Ag line and Si substrate after the firing process. To understand the effect of this layer on the electrical properties, the current-voltage analysis of the contact is carried out. The obtained results indicate that there might be locally contacted areas between Ag and Si, and these regions are distributed in laterally, which determined the carrier transportation at the contact. This SiON layer with local contacts prevents the Ag diffusion into Si crystal during the firing process, and decreases the minority carrier recombination, resulting in the relative high performances.