Self-Assembly Control of Y-Series Non-fullerene Acceptors for Sustainable and Scalable Organic Photovoltaics.

Sustainability and scalability remain critical hurdles for the commercialization of organic solar cells (OSCs). However, addressing both poses challenge. Herein, we introduce a simple yet effective strategy utilizing 3,5-dichloropyridine (PDCC) as a solid additive to fine-tune the self-assembly behavior of Y-series non-fullerene acceptors (NFAs) to tackle the upscaling limitations in green-solvent-processed OSCs. PDCC predominantly interacts with Y-series NFAs, facilitating molecular crystallization and thereby driving the self-assembly of Y-series NFAs during film-forming dynamics, leading to more uniform active layers with improved molecular packing and reduced charge recombination. As a result, PDCC-driven self-assembly strategy enables high-performance OSCs with a power conversion efficiency (PCE) of 20.47%. When translated to sustainable fabrication, this strategy significantly boosts the PCE of large-area green-solvent-processed OSC modules (19.3 cm2) from 13.87% to 15.79%, ranking it among the best-performing green-solvent-processed large-area OSC modules (> 18 cm2). Beyond its impact on PCE enhancement, PDCC serves as a multifunctional additive to improve long-term stability and exhibits strong universality across multiple material systems. This work establishes a promising approach for advancing sustainable and scalable OSCs, paving the way for their commercialization.