Effect of binding force between silver paste and silicon on power degradation of crystalline silicon solar module

• We investigate the power degradation for crystalline silicon solar cells.
• The binding force between silver paste and silicon should not be less than 2.0 N.
• The hollowed-out silver busbar weaks the binding force.

The long term reliability of crystalline solar modules is critical to the cost effectiveness and the commercial success of photovoltaic. The binding force reduction between silver paste and silicon leads to power degradation during subsequent qualification tests or outdoor using. Hence, it is very important to investigate the binding force of busbar and its influence. In this paper, the relationship between power degradation and the binding force of busbar was investigated. Significant results about binding strength of busbar were found as a result of different silver pastes. For crystalline silicon solar cells with 1.6 mm width busbar, the binding force between silver paste and silicon is not less than 2.0 N so as to let the modules made by such cells pass qualification tests. The results laid the foundation for studying the mechanical performance of front contact metallization system for screen-printed crystalline silicon solar cells.