A Water-Processed Mesoscale Structure Enables 18.5% Efficient Binary Layer-by-Layer Organic Solar Cells

Area of Science:

• Materials Science
• Renewable Energy

Background:

• Layer-by-layer (LBL) deposition is crucial for high-performance organic solar cells (OSCs) due to vertical phase separation.
• Current LBL methods for OSCs face challenges with toxic solvents and intermixing issues, hindering commercialization.

Purpose of the Study:

• To develop an eco-friendly, water-based nanoparticle (NP) ink for LBL OSCs.
• To improve the performance and processability of LBL OSCs by controlling morphology.

Main Methods:

• Fabrication of a mesoscale structure using a water-based donor polymer NP ink.
• Infiltration of the mesoscale structure with an acceptor solution using non-halogen o-xylene.
• Characterization of the resulting organic solar cells.

Main Results:

• Achieved outstanding power conversion efficiencies of 18.5% for PM6:L8-BObased LBL OSCs.
• Demonstrated enhanced charge carrier mobility and reduced trap states in the developed meso-LBL devices.
• Optimized vertical morphology through the mesoscale structure.

Conclusions:

• The water-based NP ink and mesoscale structure strategy offers a promising, eco-friendly alternative for LBL OSC fabrication.
• Findings pave the way for industrial production of efficient and sustainable organic solar cells.
• Reduced reliance on toxic solvents in OSC manufacturing.