Smartly Optimizing Crystallinity, Compatibility, and Morphology for Polymer Solar Cells by Small Molecule Acceptor with Unique 2D‐EDOT Side Chain. (17th January 2023)

• Record Type: Journal Article
• Authors: Deng, Min; Xu, Xiaopeng; Duan, Yuwei; Yu, Liyang; Li, Ruipeng; Peng, Qiang
• Is Part Of: Advanced functional materials. Volume 33:Number 12(2023)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2023-01-17
• Subjects: 2D EDOT side chains -- compatibility -- crystallinity -- morphologies -- polymer solar cells; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adfm.202212290
• Languages: English
• ISSNs: 1616-301X

Abstract

Abstract: A desired morphology is essential for achieving efficient polymer solar cells. Donors and acceptors with appropriate crystallization can lead to a suitable phase‐separated morphology for effective photocurrent generation process. Inspired by the success of Y6 acceptors and the 2D side chain engineering on popular polymer donors and small molecule acceptors, the usage of unique 2D 3, 4‐ethylene dioxythiophene (EDOT) side chains on Y6 to regulate its crystallinity, compatibility, and thus the related blend morphology is explored. In this study, two molecules of BTP‐EDOT‐4F and BTP‐EDOT‐4Cl with such unique 2D EDOT side chains are designed and synthesized. Due to the advantage of EDOT side chain, when these molecules are blended with PM6, the decent power conversion efficiencies (PCEs) of 16.78% and 15.87% are obtained. Furthermore, BTP‐EDOT‐4F is selected as the third component and added into PM6:L8‐BO binary system to form ternary blends. The optimized crystallinity, compatibility, and morphology of such ternary blend are discovered in the presence of BTP‐EDOT‐4F, which enables efficient exciton dissociation and charge transport as well as decreased recombination, resulting in higher short circuit current density ( J sc ) and fill factor. Finally, the outstanding PCE of 18.56% is achieved in ternary blends containing PM6, L8‐BO, and BTP‐EDOT‐4F. Abstract : Two small molecule acceptors with 2D 3, 4‐ethylene dioxythiophene (EDOT) side chains are designed for efficient polymer solar cells. The power conversion efficiencies (PCEs) of 16.78% and 15.87% are achieved for binary devices based on the fluorinated and chlorinated acceptors, respectively. Incorporating the fluorinated BTP‐EDOT‐4F as the third component, a champion PCE of 18.56% is achieved in ternary devices.