FMEA analysis of slot-die coating defects on the performance of 2T perovskite/silicon tandem solar cells fabricated on industry-relevant wafers

Perovskite/silicon tandem solar cells have demonstrated rapid progression of power conversion efficiency in the past decade. However, little effort has focused on integrating scalable deposition technique to industry-relevant silicon bottom cells. In particular, the relationship between coating defects and tandem cell performance loss is rarely reported. First, we discuss the effect of the silicon substrate non-ideality (trenches and texturing) on the perovskite film properties. Then, we perform a rigorous defect categorization using PL images and SEM to classify coating defects into 9 categories. Finally, we present a Failure Mode and Effects Analysis (FMEA) that reveals the three main defects causing performance loss in 2-terminal perovskite-silicon solar cells.