Publication date: 17th February 2025
Perovskite-based multijunction solar cells are on the brink of commercialization, with efficiencies skyrocketing in the past 5 years. E.g., the most efficient two-terminal configuration ever made is a perovskite/Si tandem. Yet, the reliability of these devices is still a big question mark. This is in part due to the short time since their development hindering decade-long tests due to sheer time constraints, but also because there is a lack of established accelerated aging protocols due to a lack of understanding of primary failure modes. In the presentation, I will cover our recent results looking at the perovskite cells in multijunctions and how nanometric defects trigger device degradation and how they can be mitigated. I will further discuss effects on the um- and cm-scale, e.g., how the choice of the silicon cell texturing affects performance and stability, as well as long-distance ionic effects and how precise control over different length scales enabled us to fabricate excellent wafer-scale devices beyond the state-of-the-art.