Reducing Solvent Selectivity via Solid Additive-Assisted Strategy Enables Organic Solar Cells With Approaching 21%...

Area of Science:

• Materials Science
• Organic Electronics
• Renewable Energy

Background:

• High-performance organic solar cells (OSCs) often rely on chloroform for optimal active-layer morphology.
• Chloroform's rapid film formation limits processing windows and industrial scalability.
• Reducing solvent selectivity is crucial for scalable OSC manufacturing.

Purpose of the Study:

• To address the challenge of solvent selectivity in OSC fabrication.
• To develop a strategy for modulating active-layer morphology and film formation dynamics.
• To enable high-performance OSCs using non-halogenated solvents.

Main Methods:

• A solid-additive-assisted strategy using 2,6-dimethylnaphthalene (2,6-DMN).
• Modulating film formation dynamics and molecular aggregation in various processing solvents.
• Investigating the stage-specific control of acceptor aggregation and self-assembly.

Main Results:

• 2,6-DMN effectively suppresses acceptor aggregation during spin-coating and promotes ordered self-assembly during annealing.
• This strategy leads to uniform active-layer morphology across different solvents, reducing performance variations.
• A record efficiency of 20.86% was achieved for a ternary OSC device processed from o-xylene using 2,6-DMN.

Conclusions:

• The solid-additive strategy with 2,6-DMN provides practical and efficient mitigation of solvent selectivity in OSCs.
• This approach significantly enhances processing compatibility for scalable OSC manufacturing.
• The findings demonstrate potential for developing high-performance OSCs with improved fabrication processes.