Regulating Crystallization Behavior via Non-Fused-Ring Polymer Acceptor for High Performance Ternary Organic Solar...

Area of Science:

• Materials Science
• Organic Electronics
• Photovoltaics

Background:

• Controlling active layer crystallization is crucial for organic solar cell (OSC) performance and stability.
• Non-fused-ring polymer acceptors are rarely used as ternary additives to tune crystallinity.

Purpose of the Study:

• To investigate the effect of a novel benzene-based non-fused-ring polymer acceptor (PW1) as a ternary component in OSCs.
• To enhance the power conversion efficiency (PCE) and stability of PM6:BTP-eC9 based organic solar cells.

Main Methods:

• Synthesis of PW1, a benzene-based non-fused-ring polymer acceptor.
• Incorporation of PW1 into the PM6:BTP-eC9 blend to form a ternary system.
• Characterization of film morphology, thermal stability, energy levels, and optical properties.
• Device fabrication and performance testing, including PCE, fill factor (FF), and storage stability.

Main Results:

• PW1 demonstrated good thermal stability (Td = 343°C) and miscibility with the host blend.
• PW1 acted as a compatibility modifier, suppressing aggregation and controlling crystallization of BTP-eC9.
• Ternary devices with 3 wt.% PW1 achieved a higher PCE (19.50%) compared to binary devices (18.61%).
• Improved charge extraction, longer carrier lifetimes, balanced mobilities, reduced recombination, and enhanced storage stability (T80 from 415 to 983 h) were observed.

Conclusions:

• PW1 effectively regulates active layer crystallization in organic solar cells.
• The ternary strategy significantly enhances both the efficiency and operational stability of OSCs.
• Non-fused-ring polymer acceptors show promise as effective additives for high-performance organic photovoltaics.