Inner/Outer Side Chain Engineering of Non‐Fullerene Acceptors for Efficient Large‐Area Organic Solar Modules Based on Non‐Halogenated Solution Processing in Air

Abstract

Abstract Achieving efficient and large‐area organic solar modules via non‐halogenated solution processing is vital for the commercialization yet challenging. The primary hurdle is the conservation of the ideal film‐formation kinetics and bulk‐heterojunction (BHJ) morphology of large‐area organic solar cells (OSCs). A cutting‐edge non‐fullerene acceptor (NFA), Y6, shows efficient power conversion efficiencies (PCEs) when processed with toxic halogenated solvents, but exhibits poor solubility in non‐halogenated solvents, resulting in suboptimal morphology. Therefore, in this study, the impact of modifying the inner and outer side‐chains of Y6 on OSC performance is investigated. The study reveals that blending a polymer donor, PM6, with one of the modified NFAs, namely N‐HD, achieved an impressive PCE of 18.3% on a small‐area OSC. This modified NFA displays improved solubility in o‐xylene at room temperature, which facilitated the formation of a favorable BHJ morphology. A large‐area (55 cm2) sub‐module delivered an impressive PCE of 12.2% based on N‐HD using o‐xylene under ambient conditions. These findings underscore the significant impact of the modified Y6 derivatives on structural arrangements and film processing over a large‐area module at room temperature. Consequently, these results are poised to deepen the comprehension of the scaling challenges encountered in OSCs and may contribute to their commercialization.

Keywords

• large‐area organic solar modules
• morphology control
• non‐halogenated solvents
• room temperature processing
• Y6 alkyl‐chain modification