Fig. 6: Hot water test as a pretest for module reliability. We compare cells with rear bus bars with reduced silver content (Paste A and Paste
B) with reference cells with a reference bus bar paste (cAg = 60%). Efficiency of the cells with reduced silver content in the rear bus bar paste
drops at the same time as the efficiency of the reference cells. Note that the cells are produced on a different wafer material as the cells
presented in Fig. 1.
Figure 6 shows the results of a hot water test as a first reliability test. We compare reference cells using a bus
bar paste with a silver content cAg = 60 % with cells with paste A and B. Our cells contain rear bus bars with paste
A and paste B. Every five minutes, we measure the efficiency of the cells. After 20 30 minutes, the corrosion
causes a breakdown of the efficiency. A drop of the fill factor causes the drop in efficiency. Compared to the
reference cell, the cells with reduced silver content show the same behavior as the reference cell. The efficiency
drops after the same time t > 20 min in boiling water observed at the cells with paste A and paste B and the
reference cells.
3. Conclusion