Fused-Ring Electron Acceptors as a Versatile Additive Platform for Efficient Perovskite Photovoltaics

Area of Science:

• Materials Science
• Photovoltaics
• Organic Electronics

Background:

• Perovskite solar cells (PSCs) efficiency is often limited by defects and poor reproducibility.
• Existing additives for PSCs lack a reliable molecular design platform, hindering consistent performance across research groups.

Purpose of the Study:

• To introduce a general and rational additive design platform based on fused-ring electron acceptors (FREAs) for reproducible and efficient PSCs.
• To demonstrate the versatility and reliability of FREAs in modulating perovskite film properties for improved device performance and stability.

Main Methods:

• Utilized fused-ring electron acceptors (FREAs) as a molecular design platform for additive development.
• Tailored FREA main chains to modulate energy level alignment and facilitate charge transport.
• Designed FREA side chains to induce specific film morphology and suppress ion migration.

Main Results:

• Achieved a champion power conversion efficiency of 26.66% (26.35% certified) with an optimized FREA additive.
• Demonstrated significantly improved device stability, with less than 8% efficiency loss after 2150 hours of continuous operation under 1 sun illumination.

Conclusions:

• FREA-based additives offer a reproducible and versatile platform for designing high-performance and stable perovskite solar cells.
• Strategic molecular design of FREAs enables precise control over film properties, leading to enhanced charge transport and suppressed ion migration.