Improved Ag–Si interface performance for Si solar cells using a novel Te-based glass and recrystallization process of Ag

In order to prove that the Te-based glass frit could be applied to Ag pastes to fabricate Ag electrode and elucidate the reactions among Ag, the frit, and the Si wafer, the Te-based glass and Ag pastes with different contents of glass frit (0 wt%, 1 wt%, 3 wt%, 5 wt%, and 7 wt%) were prepared. The microstructures of Ag electrodes and the phase analysis of interface between Ag electrodes and the Si wafer were investigated using scanning electron microscopy (SEM) coupled with energy-dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD). When the content of glass frit is 3 wt%, the Ag electrode has good adhesion with Si wafer. What’s more, Ag crystallites and metallic Te could be found on the Si wafer. These results suggest that the TeO₂ in the glass frit could react with SiN_x anti-reflecting coating (ARC) and Si to serve as a medium for forming Ag crystallites.