Lead(II) 2-Ethylhexanoate for Simultaneous Modulated Crystallization and Surface Shielding to Boost Perovskite Solar Cell Efficiency and Stability.

Yang, Tengteng; Zhao, Wangen; Yang, Yan; Huang, Wenliang; Zhao, Kui; Liu, Shengzhong Frank · Adv Mater · 2023

basic_science · Level V

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Abstract

The bulk and surface of a perovskite light-harvesting layer are two pivotal aspects affecting its carrier transport and long-term stability. In this work, lead(II) 2-ethylhexanoate (LDE) is introduced via an antisolvent process into perovskite films to change the reaction kinetics of the crystallization process, resulting in a high-quality perovskite film. Meanwhile, a carboxyl functional group with a long alkyl chain coordinates with the Pb cation, reducing the defect density related to unsaturated Pb atoms. Moreover, the long alkyl chains form a protecting layer at the surface of the perovskite film to prevent chemical attack by water and air, prolonging the lifetime of perovskite devices. Consequently, the assembled device demonstrates a power conversion efficiency (PCE) of 24.84%. Both of the thermal and operational stability are significantly improved due to reduced ion-migration channels.