Effects of the physical properties of bismate frits on contact formation between Ag electrodes and Si emitter in Si solar cells

To improve the performance of Si solar cells after firing, it is necessary to control the thickness of the glass layers between the Ag and Si, and the formation of Ag when it recrystallizes into the Si emitter, both of which decisively influence the performance of the cell. In this study, the effect of the physical properties of the frits on the contacts between Ag and Si is verified. Interfaces of Ag electrodes/glass layers/Ag recrystallized into n ⁺ emitter are formed when using high-fluidity frits. On the other hand, as the viscous flow of the frits slows as the temperature increases, an interface structure formed of Ag/thin glass/SiN _x layers results, with the formation of Ag nanoprecipitates in the glass layers. Our results suggest that the viscous behavior of frits under increasing temperatures leads to the formation of distinct interfaces between Ag electrodes and Si.