Abstract
Featuring simplified synthesis and flexible chemical alteration, non-fused ring electron acceptors (NFREAs) are the ideal candidates for constructing low-cost organic solar cells (OSCs). Herein, we report three A–D–A’–D–A type NFREAs, namely ffBTz-BO, ffBTz-EH, and ffBTz-C4, where difluorinated benzotriazole (ffBTz) with different side chain lengths were employed as the weak electron-deficient A’ core. Compared with ffBTz-BO and ffBTz-C4, ffBTz-EH with appropriate side chain length strikes a balance between the enhanced molecular crystallinity and the favorable face-on orientation, resulting in high charge mobilities. Consequently, ffBTz-EH-based OSC delivered the highest power conversion efficiency (PCE) of 12.96% enabled by its efficient charge transport and most suitable phase separation, which represents one of the highest efficiencies among A–D–A’–D–A type NFREAs. This work demonstrates that alkyl side chain on the central A’ core plays a critical role in tuning molecular crystallinity, active layer morphology, and further device performance, which provides a meaningful perspective for designing highly efficient A–D–A’–D–A type non-fused ring electron acceptors in the future.
摘要
非稠环电子受体(NFREA)具有合成简单和结构修饰灵活的特点, 是制备高性能低成本有机太阳电池(OSCs)的理想材料. 本工作以不同 侧链修饰的二氟苯并三氮唑(ffBTz)作为弱缺电子核(A’), 分别设计合 成了三种A–D–A’–D–A型NFREA, 即ffBTz-BO、ffBTz-EH和ffBTz-C4. 其中, ffBTz-EH, 由于其合适的侧链长度, 在分子结晶度和分子堆积优 势取向之间取得了平衡, 从而获得了更高的电荷迁移率. 并且得益于高 效的电荷传输和最合适的相分离形貌, 基于ffBTz-EH的OSC获得 12.96%的最高能量转换效率, 这也是A–D–A’–D–A型NFREA获得的最 高效率之一. 本研究表明, A’核心上的烷基侧链在调节分子结晶度、活 性层形貌和进一步调控器件性能方面起着至关重要的作用, 这为未来 设计高效低成本的A–D–A’–D–A型非稠环电子受体提供了思路.
Article PDF
Similar content being viewed by others
References
Cheng P, Li G, Zhan X, et al. Next-generation organic photovoltaics based on non-fullerene acceptors. Nat Photon, 2018, 12: 131–142
Inganäs O. Organic photovoltaics over three decades. Adv Mater, 2018, 30: 1800388
Cui C, Li Y. High-performance conjugated polymer donor materials for polymer solar cells with narrow-bandgap nonfullerene acceptors. Energy Environ Sci, 2019, 12: 3225–3246
Fukuda K, Yu K, Someya T. The future of flexible organic solar cells. Adv Energy Mater, 2020, 10: 2000765
Liu Y, Liu B, Ma CQ, et al. Recent progress in organic solar cells (Part I material science). Sci China Chem, 2021, 65: 224–268
Zhang G, Lin FR, Qi F, et al. Renewed prospects for organic photovoltaics. Chem Rev, 2022, 122: 14180–14274
Yu G, Gao J, Hummelen JC, et al. Polymer photovoltaic cells: Enhanced efficiencies via a network of internal donor-acceptor heterojunctions. Science, 1995, 270: 1789–1791
Zhu L, Zhang M, Zhong W, et al. Progress and prospects of the morphology of non-fullerene acceptor based high-efficiency organic solar cells. Energy Environ Sci, 2021, 14: 4341–4357
Lin Y, Wang J, Zhang ZG, et al. An electron acceptor challenging fullerenes for efficient polymer solar cells. Adv Mater, 2015, 27: 1170–1174
Yuan J, Zhang Y, Zhou L, et al. Single-junction organic solar cell with over 15% efficiency using fused-ring acceptor with electron-deficient core. Joule, 2019, 3: 1140–1151
Zheng Z, Wang J, Bi P, et al. Tandem organic solar cell with 20.2% efficiency. Joule, 2022, 6: 171–184
Zhu L, Zhang M, Xu J, et al. Single-junction organic solar cells with over 19% efficiency enabled by a refined double-fibril network morphology. Nat Mater, 2022, 21: 656–663
Yao H, Hou J. Recent advances in single-junction organic solar cells. Angew Chem Int Ed, 2022, 61: e202209021
Li X, Pan F, Sun C, et al. Simplified synthetic routes for low cost and high photovoltaic performance n-type organic semiconductor acceptors. Nat Commun, 2019, 10: 519
Yang M, Wei W, Zhou X, et al. Non-fused ring acceptors for organic solar cells. Energy Mater, 2022, 1: 100008
Shen Q, He C, Li S, et al. Design of non-fused ring acceptors toward high-performance, stable, and low-cost organic photovoltaics. Acc Mater Res, 2022, 3: 644–657
Mishra A, Sharma GD. Harnessing the structure-performance relationships in designing non-fused ring acceptors for organic solar cells. Angew Chem Int Ed, 2023, 62: e202219245
Luo D, Brabec CJ, Kyaw AKK. Non-fused ring electron acceptors for high-performance and low-cost organic solar cells: Structure-function, stability and synthesis complexity analysis. Nano Energy, 2023, 114: 108661
Li S, Zhan L, Liu F, et al. An unfused-core-based nonfullerene acceptor enables high-efficiency organic solar cells with excellent morphological stability at high temperatures. Adv Mater, 2018, 30: 1705208
Chen YN, Li M, Wang Y, et al. A fully non-fused ring acceptor with planar backbone and near-IR absorption for high performance polymer solar cells. Angew Chem Int Ed, 2020, 59: 22714–22720
Ma DL, Zhang QQ, Li CZ. Unsymmetrically chlorinated non-fused electron acceptor leads to high-efficiency and stable organic solar cells. Angew Chem Int Ed, 2023, 62: e202214931
Wang X, Zeng R, Lu H, et al. A simple nonfused ring electron acceptor with a power conversion efficiency over 16%. Chin J Chem, 2023, 41: 665–671
Li D, Zhang H, Cui X, et al. Halogenated nonfused ring electron acceptor for organic solar cells with a record efficiency of over 17%. Adv Mater, 2023, 36: 2310362
Miao J, Meng B, Liu J, et al. An A-D-A’-D-A type small molecule acceptor with a broad absorption spectrum for organic solar cells. Chem Commun, 2018, 54: 303–306
Liu X, Wei Y, Zhang X, et al. An A-D-A’-D-A type unfused non-fullerene acceptor for organic solar cells with approaching 14% efficiency. Sci China Chem, 2021, 64: 228–231
Deng S, Zhang L, Zheng J, et al. A simple fused-ring acceptor toward high-sensitivity binary near-infrared photodetector. Adv Opt Mater, 2022, 10: 2200371
Luo D, Jiang Z, Tan WL, et al. Non-fused ring acceptors achieving over 15.6% efficiency organic solar cell by long exciton diffusion length of alloy-like phase and vertical phase separation induced by hole transport layer. Adv Energy Mater, 2023, 13: 2203402
Pang S, Zhou X, Zhang S, et al. Nonfused nonfullerene acceptors with an A-D-A’-D-A Framework and a benzothiadiazole core for high-performance organic solar cells. ACS Appl Mater Interfaces, 2020, 12: 16531–16540
Zhou X, Pang S, Wu B, et al. Noncovalent interactions induced by fluorination of the central core improve the photovoltaic performance of A-D-A’-D-A-type nonfused ring acceptors. ACS Appl Energy Mater, 2022, 5: 7710–7718
Luo Z, Xu T, Zhang C, et al. Side-chain engineering of nonfullerene small-molecule acceptors for organic solar cells. Energy Environ Sci, 2023, 16: 2732–2758
Jiang K, Wei Q, Lai JYL, et al. Alkyl chain tuning of small molecule acceptors for efficient organic solar cells. Joule, 2019, 3: 3020–3033
Ye L, Weng K, Xu J, et al. Unraveling the influence of non-fullerene acceptor molecular packing on photovoltaic performance of organic solar cells. Nat Commun, 2020, 11: 6005
Cui Y, Yao H, Zhang J, et al. Single-junction organic photovoltaic cells with approaching 18% efficiency. Adv Mater, 2020, 32: 1908205
Zhang Z, Wang H, Yu J, et al. Modification on the indacenodithieno [3,2-b]]thiophene core to achieve higher current and reduced energy loss for nonfullerene solar cells. Chem Mater, 2020, 32: 1297–1307
Ma Y, Zhang M, Wan S, et al. Efficient organic solar cells from molecular orientation control of M-series acceptors. Joule, 2021, 5: 197–209
Zhang X, Li C, Qin L, et al. Side-chain engineering for enhancing the molecular rigidity and photovoltaic performance of noncovalently fused-ring electron acceptors. Angew Chem Int Ed, 2021, 60: 17720–17725
Qi F, Jones LO, Jiang K, et al. Regiospecific N-alkyl substitution tunes the molecular packing of high-performance non-fullerene acceptors. Mater Horiz, 2022, 9: 403–410
Price SC, Stuart AC, Yang L, et al. Fluorine substituted conjugated polymer of medium band gap yields 7% efficiency in polymer-fullerene solar cells. J Am Chem Soc, 2011, 133: 4625–4631
Clark J, Silva C, Friend RH, et al. Role of intermolecular coupling in the photophysics of disordered organic semiconductors: Aggregate emission in regioregular polythiophene. Phys Rev Lett, 2007, 98: 206406
Spano FC. The spectral signatures of Frenkel polarons in H- and J- aggregates. Acc Chem Res, 2010, 43: 429–439
Zhang M, Guo X, Ma W, et al. A large-bandgap conjugated polymer for versatile photovoltaic applications with high performance. Adv Mater, 2015, 27: 4655–4660
Blakesley JC, Castro FA, Kylberg W, et al. Towards reliable charge-mobility benchmark measurements for organic semiconductors. Org Electron, 2014, 15: 1263–1272
Kyaw AKK, Wang DH, Gupta V, et al. Intensity dependence of current-voltage characteristics and recombination in high-efficiency solution-processed small-molecule solar cells. ACS Nano, 2013, 7: 4569–4577
Street RA, Song KW, Northrup JE, et al. Photoconductivity measurements of the electronic structure of organic solar cells. Phys Rev B, 2011, 83: 165207
Mahmood A, Wang JL. A review of grazing incidence small- and wide-angle X-ray scattering techniques for exploring the film morphology of organic solar Cells. Sol RRL, 2020, 4: 2000337
Acknowledgements
The research received financial support from the Ministry of Science and Technology of China (2019YFA0705900), National Natural Science Foundation of China (U20A6002, 22275058, and 22109046), Guangdong Innovative and Entrepreneurial Research Team Program (2019ZT08L075), Guangdong Basic and Applied Basic Research Foundation (2022B1515120008), and the Start-up Founding Research and Cultivation Project funded by Ningbo University of Technology (2022KQ65 and 2022TS03).
Author information
Authors and Affiliations
Contributions
Author contributions Zhou X synthesized the electron acceptors and conducted the characterization; Zhou X and Wei W performed the data analysis. Pang S performed the photovoltaic device fabrication and characterization. Yuan X synthesized the polymer donor. Li J performed the GIWAXS measurements and data analysis. Huang F and Cao Y participated in project administration. Duan C conceived the idea and supervised the project. Zhou X, Wei W, and Duan C prepared the manuscript. All authors contributed to the general discussion.
Corresponding authors
Ethics declarations
Conflict of interest The authors declare no competing interests.
Additional information
Supplementary information Experimental details and supporting data are available in the online version of the paper.
Xia Zhou received her PhD degree in materials science and engineering from the South China University of Technology. She is currently a lecturer at Ningbo University of Technology. Her current research focuses on the design and synthesis of non-fullerene acceptors, molecular packing analysis and organic solar cells.
Wenkui Wei is currently a PhD candidate in the South China University of Technology under the supervision of Prof. Chunhui Duan. He received his bachelor and master degrees from Dalian University of Technology in 2018 and 2021. His main research interest is the design and synthesis of non-fullerene acceptors and applications in organic solar cells.
Shuting Pang received her PhD degree from the South China University of Technology in 2020. She is currently an associate professor at Hangzhou Dianzi University. Her current research interests include organic solar cells and perovskite solar cells.
Chunhui Duan received his BS degree from Dalian University of Technology in 2008 and PhD degree from the South China University of Technology in 2013. After a postdoc training at Eindhoven University of Technology, he joined the South China University of Technology as a full professor in 2017. His research interests focus on organic optoelectronic materials and their applications in solar cells, photodetectors, and transistors.
Rights and permissions
About this article
Cite this article
Zhou, X., Wei, W., Pang, S. et al. Enhanced photovoltaic performance of A–D–A’–D–A type non-fused ring electron acceptors via side chain engineering. Sci. China Mater. (2024). https://doi.org/10.1007/s40843-023-2867-6
Received:
Accepted:
Published:
DOI: https://doi.org/10.1007/s40843-023-2867-6