Advancements in low-silver metallization paste for Si solar cells

Abstract

Due to the high and sometimes volatile cost of silver metal, the need for solar cell metallization pastes with lower silver content has become imperative. At Heraeus Precious Metals, we understand the strain that silver price has placed on the PV market and want to share our customers' burden of higher cost. Extensive research has been done on the development of front-side pastes with decreased silver loading and deposit. Experimental results have indicated that a threshold exists for silver reduction; below this silver loading, the performance of the paste begins to significantly degrade. It was found that an increase in busbar-to-busbar gridline resistance with decreasing silver content was the primary source of degradation. By tailoring the solid content and morphology, as well as using proprietary additives, the performance of a low-silver paste could be improved to that of a paste with a much higher silver loading. Thus, Heraeus continues to improve the performance-to-cost ratio of its PV metallization pastes to meet market demands and customer requirements.