Rylene-Fullerene Hybrid an Emerging Electron Acceptor for High-Performing and Photothermal-Stable Ternary Solar Cells

Area of Science:

• Materials Science
• Organic Electronics
• Photovoltaics

Background:

• Perylene diimides (PDIs) are effective nonfullerene acceptors in organic solar cells (OSCs).
• Understanding the role of PDIs as a third component in ternary OSCs is limited.
• Optimizing molecular characteristics of PDIs is crucial for enhancing OSC performance and stability.

Purpose of the Study:

• To investigate the molecular design principles of perylene diimides (PDIs) as a third component in ternary organic solar cells (OSCs).
• To enhance the power conversion efficiency (PCE) and operational stability of PM6:Y6 binary OSCs by incorporating specifically designed PDIs.
• To elucidate the structure-property relationships governing the performance of ternary OSCs.

Main Methods:

• Systematic screening of various PDI derivatives with distinct molecular architectures.
• Fabrication and characterization of ternary organic solar cells (OSCs) using PM6:Y6 as the host system and selected PDIs as the third component.
• Analysis of morphological, electronic, and photophysical properties of the ternary blends.
• Long-term stability testing under continuous illumination.

Main Results:

• A rylene-fullerene hybrid PDI, S-Fuller-PMI, significantly improved the fill factor (FF) of PM6:Y6 binary OSCs from 0.72 to 0.77.
• The power conversion efficiency (PCE) of ternary OSCs increased from 15.3% to 16.2% with the incorporation of S-Fuller-PMI.
• S-Fuller-PMI demonstrated superior electron mobility and tailored compatibility with Y6, leading to improved morphology and charge transport.
• Ternary OSCs exhibited enhanced photothermal stability, retaining ~70% of initial PCE after 500 h illumination, compared to 53% for binary counterparts.

Conclusions:

• The molecular architecture of PDIs critically influences their function as a third component in ternary OSCs.
• S-Fuller-PMI acts as an effective morphological controller, enhancing charge separation and transport in PM6:Y6 based OSCs.
• The developed molecular design strategy offers a pathway for creating highly efficient and durable ternary organic solar cells (OSCs).