In-situ molecular compensation in wide-bandgap perovskite for efficient all-perovskite tandem solar cells

Journal article

Substantial VOC loss and halide segregation in wide-bandgap (WBG) perovskite sub-cells pose significant challenges for advancing all-perovskite tandem solar cells (APTSCs). Regarding this, one of the most impactful developments is the application of hole-selective self-assembled monolayers (SAMs), leading to the advancement in APTSC technology. However, SAMs with poor polar-solvent resistance would be inevitably delaminated from substrates during perovskite precursor coating, remaining great challenge in achieving a complete SAMs coverage with derivatization issues, e.g. defective perovskite and considerable interface energy loss. Here, we introduced an in-situ molecular compensation strategy to address the inherent flaw of SAMs within WBG perovskites via incorporating 5-ammonium valeric acid iodide (5-AVAI). The larger-dipole 5-AVAI spontaneously accumulates toward the buried interface to compensate the SAMs-deficient sites when depositing WBG perovskite, effectively minimizing interfacial energy loss. Simultaneously, amphoteric 5-AVAI with amino and carboxyl groups can compensate the defects at grain boundaries for solid passivation. Consequently, a champion efficiency of 20.23% with a record VOC of 1.376 V was realized on WBG devices, enabling an efficiency of 28.9% for the APTSCs. Encouragingly, the tandems showed good operational stability and retained 87.3% of their efficiency after 800 hours of tracking.

Authors: Fu, S; Sun, N; Hu, S; Chen, H; Jiang, X

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Royal Society of Chemistry
• Journal: Energy and Environmental Science
• Volume: 18
• Issue: 11
• Pages: 5503-5510
• Publication date: 2025-01-26
• Acceptance date: 2025-04-25
• DOI: 10.1039/d5ee01369k
• EISSN: 1754-5706
• ISSN: 1754-5692
• Language: English