Multifunctional Thiazolidine Derivatives Synergistic Regulation of Charge Transport Interface for Inverted Perovskite Solar Cells

Molecular passivation is an essential and efficient approach to enhancing the photovoltaic performance and operational stability of inverted perovskite solar cells (p-i-n PSCs). However, the complicated and multityped defects existing on the surface demand multifunctional materials or strategies to address these energy-loss issues. Herein, two thiazolidine derivatives, named as TZCl and TZCl-CN, characterized with sulfur atom (−S−) and secondary amine cation (−NH2+−) groups, are employed as multifunctional passivators in this work. Notably, the cyano group in the TZCl-CN offers an additional passivation effect on the perovskite/electron transport layer (ETL) interface, which has been systematically investigated. TZCl-CN modification heals the surficial defects through multisite synergistical interactions, smoothing the interface morphology, suppressing the nonradiative recombination, and accelerating charge dynamics. Consequently, a champion PCE of 26.39% has been achieved by TZCl-CN modification with improved operational stability after maximum power point tracking over 1000 h at 60 °C, which outperforms that of the TZCl-based device.