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

## TL;DR

A new strategy using 3,5-dichloropyridine improves the efficiency and scalability of organic solar cells, making them more sustainable.

## Contribution

A PDCC-assisted self-assembly method is introduced to enhance performance and scalability of organic photovoltaics.

## Key findings

- PDCC improves molecular packing and reduces charge recombination in Y-series non-fullerene acceptors.
- The method achieves 20.47% efficiency in small-area OSCs and 15.79% in large-area modules.
- The strategy is broadly applicable and improves long-term stability across multiple material systems.

## Abstract

The self-assembly behavior of Y-series non-fullerene acceptors and film formation dynamics are elucidated via in situ characterization, providing critical insights for sustainable and scalable organic solar cells (OSCs).A 3,5-dichloropyridine-assisted self-assembly strategy enables 20.47% efficiency for small-area OSCs and 15.79% for sustainable organic photovoltaic modules (19.3 cm2).This versatile self-assembly control approach is broadly applicable to various material systems, paving the way toward the commercialization of OSC.

The self-assembly behavior of Y-series non-fullerene acceptors and film formation dynamics are elucidated via in situ characterization, providing critical insights for sustainable and scalable organic solar cells (OSCs).

A 3,5-dichloropyridine-assisted self-assembly strategy enables 20.47% efficiency for small-area OSCs and 15.79% for sustainable organic photovoltaic modules (19.3 cm2).

This versatile self-assembly control approach is broadly applicable to various material systems, paving the way toward the commercialization of OSC.

The online version contains supplementary material available at 10.1007/s40820-025-02021-7.

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.

The online version contains supplementary material available at 10.1007/s40820-025-02021-7.