Passivating perovskite surface defects via bidentate chelation for high-performing solar cells

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Switzerland : 1996), 2024-10, Vol.497, p.155672, Article 155672
• Main Authors: Han, Mengting, Mo, Li’e, Yang, Zhiqian, Sun, Aiqing, Zhang, Hong, Li, Bolin, Li, Zhaoqian, Zhang, Xianxi, Ghadari, Rahim, Huang, Yang, Hu, Linhua
• Format: Article
• Language: English
• Subjects: Bidentate chelation; Carrier transport optimization; Nonradiative recombination; Perovskite solar cells
• ISSN: 1385-8947
• DOI: 10.1016/j.cej.2024.155672

[Display omitted] •Bidentate chelators enhance binding at perovskite surface defects, raising defect formation energy and curbing non-radiative recombination.•π-conjugated chelator layer aligned on the perovskite surface regulates energy levels and facilitate charge extraction.•A power conversion efficiency of 24.09% was achieved by incorporating the bidentate chelation mechanism.•Maintains over 80 % efficiency after 1000 h at 65 ± 5 % humidity due to significantly improved hydrophobicity. Surface defects seriously damage carrier transport by forming non-radiative recombination centers on the perovskite film, which negatively affect the power conversion efficiency (PCE) of perovskite solar cells (PSCs). Here we present a strong chelate coordination bond to anchor the surface of the perovskite film. Employing Bathophenanthroline (BPhen) as a π-conjugated bidentate chelator, the uncoordinated Pb2+ can be firmly anchored accompanying with the reduced surface recombination sites, giving rise to suppressed non-radiative recombination and enhanced charge carrier extraction. With the BPhen, the perovskite film shows an approximately threefold longer carrier lifetime than the control device, leading to a champion PCE of 24.09 % and a high stable performance with retained over 80 % of its initial efficiency after 1000 h exposed to relative humidity (RH) of 65 ± 5 %.