3D Polydentate Complexing Agents for Passivating Defects and Modulating Crystallinity for High‐Performance Perovskite Solar Cells. (23rd February 2023)

• Record Type: Journal Article
• Authors: Liu, Congcong; Su, Haijun; Pu, Yu; Guo, Min; Zhai, Peng; Liu, Lin; Fu, Hengzhi
• Is Part Of: Advanced functional materials. Volume 33:Number 17(2023)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2023-02-23
• Subjects: perovskite solar cells -- phytic acid -- phytic acid dipotassium -- push–pull structures -- six chemical anchor sites; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adfm.202212577
• Languages: English
• ISSNs: 1616-301X

Abstract

Abstract: The grain boundaries (GBs)/surface defects within perovskite film directly impede the further improvement of photoelectric conversion efficiency (PCE) and stability of planar perovskite solar cells (PSCs). Herein, 3D phytic acid (PA) and phytic acid dipotassium (PAD) with polydentate are explored to synchronously passivate the defects of perovskite absorber directly in multiple spatial directions. The strong electron‐donating groups (H2 PO4 ) in the PA molecule afford six anchor sites to bind firmly with uncoordinated Pb 2+ at the GBs/surface and modulate perovskite crystallization, thus enhancing the quality of perovskite film. Particularly, PAD containing an additional (K→PO) push–pull structure promotes the dominant coordination of phosphate group (PO) with Pb 2+ and passivates halide anion defects due to the complexation of potassium ions (K + ) with iodide ions (I ‐ ). Consequently, the PAD‐complexed PSCs deliver a champion PCE of 23.18%, which is remarkably higher than that of the control device (19.94%). Meanwhile, PAD‐complexed PSCs exhibit superior moisture and thermal stability, remaining 79% of their initial PCE after 1000 h under continuous illumination, while the control device remain only 48% of their PCE after 1000 h. This work provides important insights into designing multifunctional 3D passivators for the purpose of simultaneously enhancing the efficiency and stability of devices. Abstract : 3D polydentate complexing agents are explored to synchronously passivate defects of perovskite absorber directly in multiple spatial directions. The strong electron‐donating groups (H2 PO4 ) in the phytic acid can passivate non‐coordinated Pb 2+ at the ground boundaries/surface and modulate perovskite crystallization. Especially, phytic acid dipotassium (PAD) containing additional (K→PO) push–pull structure passivates the amphoteric defects. Therefore, the PAD‐passivated perovskite solar cells deliver a champion photoelectric conversion efficiency of 23.18%.