Effect of basicity of glass frits on electrical properties of Si solar cells

The purpose of this study is to understand the effects of the basicity parameter of glass frits added to the front contact of three-busbar Si solar cells on the removal of the anti-reflective coating (ARC) and the electrical characteristics of the cell. We investigated PbO-TeO₂-SiO₂ glass systems by adding oxides to improve the etching of the interface between the Ag electrode and the Si wafer. The thermal properties and viscous flows of the frits were characterized using differential thermal analysis and a hot-stage microscope. The microstructure of the glass layer at the interface of the Ag electrode and Si wafer was observed using scanning electron microscopy and transmission electron microscopy. The results showed that the electrical properties were dependent on the morphology of the interfacial structure. The addition of oxides to the glass system produced more recrystallites on the n⁺ emitter with a greater penetration depth in the Si wafer, thereby increasing the efficiency of the solar cell. The reactivity of the glass affected the removal of the ARC and the electrical properties of the Si solar cells were influenced by the charge transport facilitated by the Ag crystallites.