Dithienopyrrolothiophene (DTPT) based acceptors for fine-tuning molecular packing and enhancing ternary organic photovoltaic performance

• Published in: Journal of materials chemistry. C, Materials for optical and electronic devices Materials for optical and electronic devices, 2024-11, Vol.12 (44), p.17966-17976
• Main Authors: Jiang, Bing-Huang, Afraj, Shakil N, Ezhumalai, Yamuna, Chang, Chun-Yen, Yang, Yun-Hsuan, Su, Yu-Wei, Abdelhady, Ahmed L, Li, Yu-Qi, Shi, Zhong-En, Liu, Cheng-Liang, Chen, Ming-Chou, Kao, Hsien-Ming, Chen, Chih-Ping
• Format: Article
• Language: English
• Subjects: Carrier mobility; Carrier recombination; Chain branching; Comparative studies; Current carriers; Energy conversion efficiency; Energy harvesting; Energy levels; Halogens; Morphology; Optical properties; Optoelectronics; Photovoltaic cells; Preferred orientation; X-ray scattering
• ISSN: 2050-7526; 2050-7534
• DOI: 10.1039/d4tc03335c

The ternary strategy boosts the performance of organic photovoltaics (OPVs) by optimizing light-harvesting, blend morphology, and energy level alignment. Three novel non-fullerene acceptors (NFAs), IN-DTPT-b20 ( 1 ), IN F -DTPT-b20 ( 2 ), and IN Cl -DTPT-b20 ( 3 ), have been designed and synthesized. These NFAs feature a dithienopyrrolothiophene (DTPT)-based fused ring core with soluble branched alkyl side chains and indanone-based end groups, which are functionalized with different halogens (H, F, Cl) to modulate the electronic properties of the NFAs. A comparative study of the thermal, optical, electrochemical, and computed electronic structural properties of compounds 1-3 was conducted. We investigated the optoelectronic properties of PM6:Y6 based OPV in the presence of 1-3 as third component. Following optimization, the power conversion efficiency (PCE) of the ternary OPV based on IN-DTPT-b20 ( 1 ) was significantly enhanced from 15.17 ± 0.28% ( PM6:Y6 ) to 16.20 ± 0.26%. Tapping-mode atomic force microscopy (AFM) and grazing-incidence wide-angle X-ray scattering (GIWAXS) analysis confirmed that incorporating IN-DTPT-b20 ( 1 ) into PM6:Y6 blend films effectively tailored the blend morphology, particularly by modulating the preferred orientation of Y6 . The optimized morphology resulted in enhanced carrier mobility, reduced trap-assisted recombination, and efficient charge collection. These findings demonstrate the effectiveness of our NFA design strategy, further bolstered by the incorporation of IN-DTPT-b20 ( 1 ) as a guest acceptor, for achieving efficient OPV. The ternary strategy boosts the performance of organic photovoltaics (OPVs) by optimizing light-harvesting, blend morphology, and energy level alignment.