Dynamic Disulfide-Linked Dimeric Acceptors for High-Efficiency and Mechanically Robust Organic Solar Cells

Area of Science:

• Materials Science
• Organic Electronics
• Polymer Chemistry

Background:

• Organic solar cells (OSCs) are crucial for wearable electronics, but require enhanced efficiency, stability, and mechanical properties.
• Existing OSC materials often lack the necessary robustness for demanding applications.

Purpose of the Study:

• To develop a new photoactive material for OSCs with improved efficiency and mechanical durability.
• To investigate the role of dynamic covalent linkages in enhancing OSC performance and stability.

Main Methods:

• Synthesis of a disulfide-linked dimeric acceptor (DY-SS) with exchangeable dynamic covalent linkages.
• Fabrication and characterization of ternary organic solar cell devices incorporating DY-SS.
• Mechanical testing including bending cycles and toughness measurements.

Main Results:

• The DY-SS material improved power conversion efficiency (PCE) to 20.40% and extended thermal lifetime (T80) by 1.62-fold.
• The adaptive covalent network formed via disulfide exchange enhanced film toughness (7.54-fold) and crack-onset strain (16.07%).
• Toughened flexible OSCs retained 91.1% efficiency after 100,000 bending cycles with a 1 mm radius.

Conclusions:

• The disulfide-linked dimeric acceptor provides a viable molecular design strategy for efficient and mechanically robust OSCs.
• Dynamic covalent chemistry offers a pathway to create adaptive materials for demanding electronic applications.
• This work demonstrates significant progress towards practical OSCs for flexible and wearable devices.