Coassembled Self-Assembled Monolayers Enable Efficient and Stable Inverted Perovskite Solar Cells

Area of Science:

• Materials Science
• Renewable Energy
• Nanotechnology

Background:

• Self-assembled monolayers (SAMs) are crucial in perovskite solar cells (PSCs).
• Molecular aggregation and interfacial energy loss in SAMs limit PSC efficiency and stability.
• Existing SAM strategies face challenges in achieving optimal interfacial properties.

Purpose of the Study:

• To develop a molecular regulation strategy for coassembling SAMs in inverted PSCs.
• To address molecular aggregation and energy loss at the buried interface.
• To enhance the efficiency and long-term stability of PSCs.

Main Methods:

• Coassembly of 1,3-diaminopropane dihydroiodide (PDADI) and MeO-2PACz to form SAMs.
• Investigating the impact of PDADI on MeO-2PACz molecular aggregation and homogeneity.
• Analyzing interfacial properties, perovskite film characteristics, and device performance.

Main Results:

• PDADI introduction inhibited MeO-2PACz aggregation, improving SAM homogeneity and interfacial anchoring.
• Enhanced hole extraction and reduced nonradiative recombination at the interface were observed.
• Perovskite films exhibited improved crystallinity, uniformity, reduced defect density, and residual stress.
• Achieved a champion power conversion efficiency (PCE) of 25.49% for single devices and 22.09% for mini-modules.
• Demonstrated improved device stability, retaining 93% efficiency after 1000 hours of operation.

Conclusions:

• The coassembly strategy effectively regulates SAMs for enhanced PSC performance.
• Improved interfacial properties translate to higher efficiency and significantly better operational stability.
• This approach offers a promising pathway for developing highly efficient and stable perovskite solar cells.