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 TeO_(2) in the glass frit could react with SiNx anti-reflecting coating(ARC)and Si to serve as a medium for forming Ag crystallites.

Application of Te-Based Glass in Silicon Solar Cells

（90-x）TeO2-xZnO-lOBi203 （x = 15, 17.5, 20 and 22.5, in mol%） and 70TeOz-2OZnO-（10-y）Bi2O3-y Na2O （y = 1, 3, 5, 7, and 10, in mol%） glasses, and the corresponding Ag paste were prepared in order to prove that the Te-based glass frit could be applied to Ag pastes to fabricate Ag electrode. The relationship between structure and properties of the glasses was analyzed. The effects of glass frit on the microstructure, adhesion force, and resistivity of the Ag electrode were studied. The microstructure of Ag electrodes and the phase analysis of interface between Ag electrodes and the Si wafer were investigated using SEM and XRD. Finally, the 70TeO2-20ZnO-5Bi2O3-5Na2O glass showed better performance in the paste. What is more, Ag crystallites could be found on the Si wafer. These results suggested that the Te-based glass frit could react with SiNx anti-reflecting coating and Si to serve as a medium for forming Ag crystallites.