Steady‐State Performance Measurements of State‐of‐the‐Art Perovskite Solar Cells

Reliable steady‐state testing protocols are crucial for accurately evaluating the performance of perovskite solar cells. In this study, we systematically compare the asymptotic P MAX scan and the maximum power point tracking (MPPT) method to assess their effectiveness in steady‐state efficiency measurements. We introduce the current density standard deviation factor as a stability criterion in the asymptotic P MAX scan, and implement a convergence amplitude to regulate the voltage adjustment speed toward the maximum power point. There is a possible tendency that the performance of state‐of‐the‐art perovskite solar cells improved in the asymptotic P MAX scan in low‐to‐high voltage directions. Numerical device simulations reveal that this improvement is due to a reduction in the trap state density in both the perovskite bulk and at the interfaces. We further compare asymptotic P MAX scans conducted in both low‐to‐high and high‐to‐low voltage directions, demonstrating their strong consistency and repeatability on state‐of‐the‐art perovskite solar cells. Our results show that the steady‐state P MAX obtained from the asymptotic P MAX scan closely matches, but can be slightly higher than, that from MPPT. This work provides a comprehensive evaluation of steady‐state testing methods for perovskite solar cells, offering a foundation for more accurate performance characterization and certification.