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

Abstract

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.