Stereoelectronic manipulation of ligands for perovskite solar cells

"Interfacial losses at perovskite/charge transport layer heterojunctions persist as a critical barrier to achieving high-performance perovskite solar cells. While molecular ligands can passivate interfacial vacancy defects, their vertical anchoring geometry compromises charge transport by increasing interfacial transport pathway. Here, we demonstrate that stereoelectronic manipulation of ligand adsorption topology advances interfacial minimum energy loss for efficient and stable perovskite solar cells."

"By strategically replacing benzene carbons with nitrogen atoms to create pyridine or pyrimidine rings, we design ligands that concurrently anchor to the perovskite through Pb-N coordination bonds and Pb-I- interactions, endowing a single molecule with dual, synergistic binding modes. This mutually reinforcing stereoelectronic interplay drives thermodynamically favorable planar alignment of ligands, enabling atomic-scale defect mitigation while maintaining sub-nanometer-scale charge transfer across the interface."

"The optimized interfacial architecture achieves a stabilized power output of 26.85%, with certificated reverse-sca"

Interfacial losses at perovskite/charge transport layer heterojunctions limit high-performance perovskite solar cells. Molecular ligands can passivate interfacial vacancy defects, but vertical anchoring geometry can hinder charge transport by lengthening interfacial transport pathways. A stereoelectronic approach manipulates ligand adsorption topology to improve interfacial minimum energy loss. Ligands are engineered by replacing benzene carbons with nitrogen atoms to form pyridine or pyrimidine rings. These ligands anchor to the perovskite through Pb–N coordination bonds and through Pb–I interactions, providing dual synergistic binding modes within a single molecule. The stereoelectronic interplay promotes thermodynamically favorable planar ligand alignment, enabling atomic-scale defect mitigation while maintaining sub-nanometer charge transfer across the interface. The optimized architecture yields a stabilized power output of 26.85% and supports certified reverse-scan performance.

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