Effect of TeO2 on Ag/Si interface contact of crystalline silicon solar cells

Abstract

• The effects of TeO 2 on the sintering of c-Si solar cell are systematically studied. • TeO 2 affects the morphology of the grids on the sintering process of Ag pastes. • TeO 2 promotes Ag pastes sintering and improves the conductivity of Ag grids. • TeO 2 promotes the growth of the Ag nanocrystallites in Ag/Si contact interface. • An optimal conversion efficiency of solar cells was acquired at TeO 2 content ∼40%. Glass frits, as a critical ingredient, plays an important role between Ag electrode and crystalline silicon (c-Si) solar cells and determines sintering properties of the silver paste and contact quality with c-Si solar cells. Here glass frits with different contents of TeO 2 are prepared and used to investigate the sintering process and effects of contact quality of Ag pastes on c-Si solar cells. Microstructures and electrical properties of the Ag/Si contact interface and performances of the resultant c-Si solar cells are characterized systematically. The results show that TeO 2 promotes the growth of Ag nanocrystallites in the glass layer between Ag grids and c-Si wafers, thus reduces the contact resistance of the Ag grids and improves the contact quality of the Ag/Si interfaces. Moreover, TeO 2 improves the densification and conductive performances of the Ag grids. However, excessive TeO 2 has a negative effect on the conductivity of the Ag grid due to the increased thickness of the glass layer. Based on the competing factors played by TeO 2 , the conversion efficiency is the highest at an optimized TeO 2 content ∼40%.