King Abdullah University of Science and Technology (KAUST), KAUST Solar Center (KSC), Physical Sciences and Engineering Division (PSE), Thuwal, Kingdom of Saudi Arabia
King Abdullah University of Science and Technology (KAUST), KAUST Solar Center (KSC), Physical Sciences and Engineering Division (PSE), Thuwal, Kingdom of Saudi Arabia
King Abdullah University of Science and Technology (KAUST), KAUST Solar Center (KSC), Physical Sciences and Engineering Division (PSE), Thuwal, Kingdom of Saudi Arabia
The stability of perovskite-based tandem solar cells (TSCs) is the last major scientific/technical challenge to be overcome before commercialization. Understanding the impact of mobile ions on the TSC performance is key to minimizing degradation. Here, we present a comprehensive study that combines an experimental analysis of ionic losses in Si/perovskite and all-perovskite TSCs using scan-rate-dependent current-voltage (J-V) measurements with drift-diffusion simulations. Our findings demonstrate that mobile ions have a significant influence on the tandem cell performance, lowering the ion-freeze power conversion efficiency from >31% for Si/perovskite and >30% for all-perovskite tandems to around 28% in steady-state. Moreover, the ions cause a substantial hysteresis in Si/perovskite and all-perovskite TSCs at high scan speeds (400 V/s and 40 V/s, respectively), and significantly influence the performance degradation due to field screening. Additionally, for all-perovskite tandems, subcell-dominated measurements reveal more pronounced ionic losses in the wide-bandgap subcell during aging, which we attribute to its tendency for halide segregation. This work provides valuable insights into ionic losses in perovskite-based TSCs, which helps to separate ion migration-related degradation modes from other degradation mechanisms and guides targeted interventions for enhanced subcell efficiency and stability.
This is an Open Access abstract, distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution and reproduction in any medium or format, provided the original work is properly cited.
Perovskite-based Tandem Solar Cells, Mobile Ions, Ionic Losses, Wide-bandgap, Low-bandgap, Subcell Dominating Fast Hysteresis Measurements, Light Aging, Degradation