Design of Perovskite Thermally Co-Evaporated Highly Efficient Mini-Modules with High Geometrical Fill Factors

Perovskite solar cells (PSCs) have emerged as a promising technology for next-generation photovoltaics thanks to their high power-conversion-efficiency (PCE). Scaling up PSCs using industrially compatible processes is a key requirement to make them suitable for a variety of applications. Herein, large-area PSCs and perovskite solar modules (PSMs) are developed based on co-evaporated MAPbI₃ using optimized structures and active area designs to enhance PCEs and geometrical fill factors (GFFs). Small-area co-evaporated PSCs (0.16 cm²) achieve PCE over 19%. When the PSCs are scaled-up, the thin films high quality allows them to maintain consistent V_oc and J_sc, while their fill factors (FF), which depend on the substrate sheet resistance, are substantially compromised. However, PSCs with active areas from 1.4 to 7 cm² show a substantially improved FF when rectangular designs with optimized length to width ratios are used. Reasoning these results in the PSM design with optimal subcell size and for specific dead areas, a 6.4 cm² PSM is demonstrated with a record 18.4% PCE and a GFF of ≈91%. Combining the high uniformity of the co-evaporation deposition with active areas design, it is possible to scale up 40 times the PSCs with PCE losses smaller than 0.7% (absolute value).