Recent Progress in Fused-Ring Based Nonfullerene Acceptors for Polymer Solar Cells

Area of Science:

• Materials Science
• Organic Electronics
• Photovoltaics

Background:

• Bulk-heterojunction (BHJ) polymer solar cells (PSCs) rely on photoactive donor and acceptor materials.
• Fullerene derivatives have dominated PSC acceptors but have limitations in absorption and tunability.
• Nonfullerene acceptors (NFAs) offer improved performance and design flexibility.

Purpose of the Study:

• To review recent advancements in fused-ring based A-D-A type nonfullerene acceptors for PSCs.
• To analyze the correlation between molecular structures and photovoltaic properties of these NFAs.
• To provide insights for designing high-efficiency NFAs.

Main Methods:

• Focus on fused-ring based A-D-A type nonfullerene acceptors.
• Discussion of molecular structure, energy levels (HOMO), absorption spectra (visible-NIR), and aggregation properties.
• Correlation of these properties with device performance metrics like open-circuit voltage and short-circuit current density.

Main Results:

• Fused-ring based NFAs exhibit strong visible-NIR absorption and low HOMO levels.
• Structural design allows flexible tuning of electronic and optical properties.
• These NFAs have driven PSC power conversion efficiency beyond 13%.

Conclusions:

• Fused-ring based NFAs are promising alternatives to fullerenes in PSCs.
• Understanding structure-property relationships is crucial for further NFA development.
• Continued research in NFA design will enhance PSC efficiency and applicability.