23.2% efficient low band gap perovskite solar cells with cyanogen management
Perera, W. H. K.; Zhou, Y.; Webb, T.; Trindade, G. F.; Xu, Y.; Zhu, J.; Masteghin, M. G.; Harvey, S. P.; Macdonald, T. J.; Jenatsch, S.; Dai, L.; Sathasivam, S.; Hinder, S. J.; Stranks, S. D.; Jayawardena, K. D. G. I.; Zhao, D.; Zhao, Y.; Zhang, W.; Haque, S. A.; Silva, S. R. P.
Energy Environ. Sci. 2025, 18, 439–453. https://doi.org/10.1039/d4ee03001j.
The main goal of this study was to improve the efficiency and stability of low-bandgap lead–tin perovskite solar cells (PSCs) by addressing degradation linked to iodine formation and interactions at the PEDOT:PSS hole transport layer interface.
Key findings revealed that organic cations de-dope PEDOT:PSS, leading to performance losses, which thiocyanate additives can partially mitigate. However, thiocyanates introduce a new degradation pathway via cyanogen formation in humid conditions. Incorporating an iodine-reducing agent (benzylhydrazine chloride, BHC) successfully improved both efficiency and stability, achieving a record 23.2% power conversion efficiency and a 66% increase in TS80 lifetime under ambient conditions.
Fluxim's tools played a crucial role in this research: Paios enabled detailed electrical characterization such as transient photocurrent and impedance spectroscopy, while Setfos was used for optical simulations. These tools provided critical insights into carrier dynamics, interface behavior, and trap states, helping to validate the underlying mechanisms affecting device performance.
The findings are significant for the scientific community as they offer new chemical strategies to design more stable and efficient PSCs, particularly critical for scaling up perovskite-based multijunction solar technologies.