Abstract
Clusters of water molecules have low ionization energies because of stabilization of charge from the dipole moment of surrounding molecules, and thus can form potential traps resulting in the undesirable photovoltaic performance in organic solar cells (OSCs). Herein, we demonstrated a solvent-water evaporation (SWE) strategy, which can effectively remove the water-induced traps that are omnipresent in photoactive layers, leading to a significant improvement in device performance. A higher power conversion efficiency of 17.10% and a better device photostability are achieved by using this SWE method, as compared with the untreated binary PM6:Y6 system (15.83%). We highlight the water-related traps as a limiting factor for carrier transport and extraction properties, and further reveal the good universality of the SWE strategy applied into OSCs. In addition, organic light-emitting diodes and organic field-effect transistors are investigated to demonstrate the applicability of this SWE approach. This strategy presents a major step forward for advancing the field of organic electronics.
摘要
由于水分子簇的电离能较低, 在有机共轭材料中, 水致缺陷有可能在膜中分子间的空隙形成. 这就导致了较差的空穴和电子传输能力, 使有机太阳能电池的光伏性能变差. 本工作研发了一种溶剂-水蒸发(SWE)策略, 该策略可以有效去除光敏层中无处不在的水诱导陷阱, 从而显著改善器件性能. 与未经处理的PM6:Y6二 元体系(15.83%)相比, 使用这种SWE方法可实现该体系17.10%的功 率转换效率和更好的器件光稳定性. 本文还揭示了该策略的独特优势, 包括良好的电荷传输和提取特性以及在有机太阳能电池中的良好通用性. 此外, 我们将该策略应用于有机发光二极管和有机场效应晶体管, 证明了该SWE方法的普适性. 这一策略为推进有机电子学领域的发展迈出了重要的一步.
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Li S, Li CZ, Shi M, et al. New phase for organic solar cell research: Emergence of Y-series electron acceptors and their perspectives. ACS Energy Lett, 2020, 5: 1554–1567
Fukuda K, Yu K, Someya T. The future of flexible organic solar cells. Adv Energy Mater, 2020, 10: 2000765
Lee C, Lee S, Kim GU, et al. Recent advances, design guidelines, and prospects of all-polymer solar cells. Chem Rev, 2019, 119: 8028–8086
Guo J, Min J. A cost analysis of fully solution-processed ITO-free organic solar modules. Adv Energy Mater, 2019, 9: 1802521
Wang T, Sun R, Shi M, et al. Solution-processed polymer solar cells with over 17% efficiency enabled by an iridium complexation approach. Adv Energy Mater, 2020, 10: 2000590
Luo Z, Ma R, Liu T, et al. Fine-tuning energy levels via asymmetric end groups enables polymer solar cells with efficiencies over 17%. Joule, 2020, 4: 1236–1247
Cui Y, Yao H, Zhang J, et al. Single-junction organic photovoltaic cells with approaching 18% efficiency. Adv Mater, 2020, 32: 1908205
Yang W, Luo Z, Sun R, et al. Simultaneous enhanced efficiency and thermal stability in organic solar cells from a polymer acceptor additive. Nat Commun, 2020, 11: 1218
Yao H, Wang J, Xu Y, et al. Recent progress in chlorinated organic photovoltaic materials. Acc Chem Res, 2020, 53: 822–832
Zhao J, Li Y, Yang G, et al. Efficient organic solar cells processed from hydrocarbon solvents. Nat Energy, 2016, 1: 15027
Sun R, Wang T, Luo Z, et al. Achieving eco-compatible organic solar cells with efficiency >16.5% based on an iridium complex-incorporated polymer donor. Sol RRL, 2020, 4: 2000156
Liu Q, Jiang Y, Jin K, et al. 18% Efficiency organic solar cells. Sci Bull, 2020, 65: 272–275
Cheng P, Yang Y. Narrowing the band gap: The key to highperformance organic photovoltaics. Acc Chem Res, 2020, 53: 1218–1228
Zheng Z, Yao H, Ye L, et al. PBDB-T and its derivatives: A family of polymer donors enables over 17% efficiency in organic photovoltaics. Mater Today, 2019, 35: 115–130
Wang W, Chen B, Jiao X, et al. A new small molecule donor for efficient and stable all small molecule organic solar cells. Org Electron, 2019, 70: 78–85
Wan X, Li C, Zhang M, et al. Acceptor-donor-acceptor type molecules for high performance organic photovoltaics—chemistry and mechanism. Chem Soc Rev, 2020, 49: 2828–2842
Li X, Huang G, Chen W, et al. Size effect of two-dimensional conjugated space in photovoltaic polymers’ side chain: Balancing phase separation and charge transport. ACS Appl Mater Interfaces, 2020, 12: 16670–16678
Heumueller T, Mateker WR, Sachs-Quintana IT, et al. Reducing burn-in voltage loss in polymer solar cells by increasing the polymer crystallinity. Energy Environ Sci, 2014, 7: 2974–2980
Min J, Jiao X, Ata I, et al. Time-dependent morphology evolution of solution-processed small molecule solar cells during solvent vapor annealing. Adv Energy Mater, 2016, 6: 1502579
Han YW, Jeon SJ, Lee HS, et al. Evaporation-free nonfullerene flexible organic solar cell modules manufactured by an all-solution process. Adv Energy Mater, 2019, 9: 1902065
Zuo G, Linares M, Upreti T, et al. General rule for the energy of water-induced traps in organic semiconductors. Nat Mater, 2019, 18: 588–593
Kotadiya NB, Mondal A, Blom PWM, et al. A window to trap-free charge transport in organic semiconducting thin films. Nat Mater, 2019, 18: 1182–1186
Nicolai HT, Kuik M, Wetzelaer GAH, et al. Unification of traplimited electron transport in semiconducting polymers. Nat Mater, 2012, 11: 882–887
Guo J, Wu Y, Sun R, et al. Suppressing photo-oxidation of nonfullerene acceptors and their blends in organic solar cells by exploring material design and employing friendly stabilizers. J Mater Chem A, 2019, 7: 25088–25101
Adams J, Salvador M, Lucera L, et al. Water ingress in encapsulated inverted organic solar cells: Correlating infrared imaging and photovoltaic performance. Adv Energy Mater, 2015, 5: 1501065
Scholz S, Kondakov D, Lüssem B, et al. Degradation mechanisms and reactions in organic light-emitting devices. Chem Rev, 2015, 115: 8449–8503
Nikolka M, Schweicher G, Armitage J, et al. Performance improvements in conjugated polymer devices by removal of water-induced traps. Adv Mater, 2018, 30: 1801874
Gomes HL, Stallinga P, Cölle M, et al. Electrical instabilities in organic semiconductors caused by trapped supercooled water. Appl Phys Lett, 2006, 88: 082101
Tsai MJ, Meng HF. Electron traps in organic light-emitting diodes. J Appl Phys, 2005, 97: 114502
Nikolka M, Broch K, Armitage J, et al. High-mobility, trap-free charge transport in conjugated polymer diodes. Nat Commun, 2019, 10: 2122
Nikolka M, Nasrallah I, Rose B, et al. High operational and environmental stability of high-mobility conjugated polymer field-effect transistors through the use of molecular additives. Nat Mater, 2017, 16: 356–362
Sun R, Wu Q, Guo J, et al. A layer-by-layer architecture for printable organic solar cells overcoming the scaling lag of module efficiency. Joule, 2020, 4: 407–419
Sun R, Deng D, Guo J, et al. Spontaneous open-circuit voltage gain of fully fabricated organic solar cells caused by elimination of interfacial energy disorder. Energy Environ Sci, 2019, 12: 2518–2528
Sun R, Guo J, Sun C, et al. A universal layer-by-layer solution-processing approach for efficient non-fullerene organic solar cells. Energy Environ Sci, 2019, 12: 384–395
Wang W, Wu Q, Sun R, et al. Controlling molecular mass of low-band-gap polymer acceptors for high-performance all-polymer solar cells. Joule, 2020, 4: 1070–1086
Min J, Güldal NS, Guo J, et al. Gaining further insight into the effects of thermal annealing and solvent vapor annealing on time morphological development and degradation in small molecule solar cells. J Mater Chem A, 2017, 5: 18101–18110
Gurney RS, Lidzey DG, Wang T. A review of non-fullerene polymer solar cells: From device physics to morphology control. Rep Prog Phys, 2019, 82: 036601
Zhao F, Wang C, Zhan X. Morphology control in organic solar cells. Adv Energy Mater, 2018, 8: 1703147
Huang Y, Kramer EJ, Heeger AJ, et al. Bulk heterojunction solar cells: Morphology and performance relationships. Chem Rev, 2014, 114: 7006–7043
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
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
Min J, Kwon OK, Cui C, et al. High performance all-small-molecule solar cells: Engineering the nanomorphology via processing additives. J Mater Chem A, 2016, 4: 14234–14240
Yu R, Yao H, Hong L, et al. Design and application of volatilizable solid additives in non-fullerene organic solar cells. Nat Commun, 2018, 9: 4645
Nicolai HT, Mandoc MM, Blom PWM. Electron traps in semiconducting polymers: Exponential versus Gaussian trap distribution. Phys Rev B, 2011, 83: 195204
Zuo G, Li Z, Andersson O, et al. Molecular doping and trap filling in organic semiconductor host-guest systems. J Phys Chem C, 2017, 121: 7767–7775
Mandoc MM, de Boer B, Paasch G, et al. Trap-limited electron transport in disordered semiconducting polymers. Phys Rev B, 2007, 75: 193202
Min J, Jiao X, Sgobba V, et al. High efficiency and stability small molecule solar cells developed by bulk microstructure fine-tuning. Nano Energy, 2016, 28: 241–249
Min J, Luponosov YN, Gasparini N, et al. Effects of alkyl terminal chains on morphology, charge generation, transport, and recombination mechanisms in solution-processed small molecule bulk heterojunction solar cells. Adv Energy Mater, 2015, 5: 1500386
Karki A, Vollbrecht J, Gillett AJ, et al. The role of bulk and interfacial morphology in charge generation, recombination, and extraction in non-fullerene acceptor organic solar cells. Energy Environ Sci, 2020, 13: 3679–3692
Vollbrecht J, Brus VV, Ko SJ, et al. Quantifying the nongeminate recombination dynamics in nonfullerene bulk heterojunction organic solar cells. Adv Energy Mater, 2019, 9: 1901438
Brus VV, Proctor CM, Ran NA, et al. Capacitance spectroscopy for quantifying recombination losses in nonfullerene small-molecule bulk heterojunction solar cells. Adv Energy Mater, 2016, 6: 1502250
Albrecht S, Tumbleston JR, Janietz S, et al. Quantifying charge extraction in organic solar cells: The case of fluorinated PCPDTBT. J Phys Chem Lett, 2014, 5: 1131–1138
Proctor CM, Kim C, Neher D, et al. Nongeminate recombination and charge transport limitations in diketopyrrolopyrrole-based solution-processed small molecule solar cells. Adv Funct Mater, 2013, 23: 3584–3594
Karki A, Vollbrecht J, Dixon AL, et al. Understanding the high performance of over 15% efficiency in single-junction bulk heterojunction organic solar cells. Adv Mater, 2019, 31: 1903868
Zhu W, Spencer AP, Mukherjee S, et al. Crystallography, morphology, electronic structure, and transport in non-fullerene/nonindacenodithienothiophene polymer: Y6 solar cells. J Am Chem Soc, 2020, 142: 14532–14547
Heiber MC, Okubo T, Ko SJ, et al. Measuring the competition between bimolecular charge recombination and charge transport in organic solar cells under operating conditions. Energy Environ Sci, 2018, 11: 3019–3032
Bartesaghi D, Pérez IDC, Kniepert J, et al. Competition between recombination and extraction of free charges determines the fill factor of organic solar cells. Nat Commun, 2015, 6: 1
Wang T, Sun R, Xu S, et al. A wide-bandgap D-A copolymer donor based on a chlorine substituted acceptor unit for high performance polymer solar cells. J Mater Chem A, 2019, 7: 14070–14078
Yang W, Guo J, Sun R, et al. Finely tuned cores in star-shaped zwitterionic molecules for interface engineering of high-performance polymer solar cells. Sol RRL, 2019, 3: 1900166
Sun R, Wu Y, Guo J, et al. High-efficiency all-small-molecule organic solar cells based on an organic molecule donor with an asymmetric thieno[2,3-f] benzofuran unit. Sci China Chem, 2020, 63: 1246–1255
Wang C, Zhang X, Hu W. Organic photodiodes and phototransistors toward infrared detection: Materials, devices, and applications. Chem Soc Rev, 2020, 49: 653–670
Xiao X, Pan G, Li T, et al. Magnetic-field guided solvent vapor annealing for enhanced molecular alignment and carrier mobility of a semiconducting diketopyrrolopyrrole-based polymer. J Mater Chem C, 2020, 8: 4477–4485
Acknowledgements
This work was supported by the National Natural Science Foundation of China (NSFC) (51773157 and 52061135206), and the Fundamental Research Funds for the Central Universities. The authors also thank the support of the opening project of Key Laboratory of Materials Processing and Mold and Beijing National Laboratory for Molecular Sciences (BNLMS201905). We thank Yihua Chen and Huanping Zhou for conducting the thermal admittance spectroscopy (TAS) measurements.
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Author contributions Shi M and Min J conceived the ideas and coordinated the work. Shi M designed the experiments, performed the fabrication of solar cell devices and data analysis. Wang T contributed to the donor polymer materials. Wu Y contributed to the acceptor materials. Xie G conducted the OLED performance measurement. Pei D and Ye L conducted the fabrication of OFET devices and their performance measurement. Wang H and Wang T did the capacitance spectroscopy measurements. Sun R and Wu Q did the atomic force microscopy measurements. Yang W and Wang W did the transient physics measurements. Shi M and Min J contributed to manuscript preparation, and Shi M supervised by Min J conceived and directed the project. All authors commented on the manuscript.
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Mumin Shi received a BSc degree from Northwest Agriculture & Forestry University in 2018. Now she is pursuing her MSc degree at the Institute for Advanced Studies, Wuhan University and her research focuses on the material and device stability in organic solar cells.
Jie Min is a full professor at the Institute for Advanced Studies, Wuhan University. During 2008–2011, he focused on the photovoltaic materials in the group of prof. Yongfang Li as a joint master. In 2015, he completed his PhD study in the Institute of Materials for Electronics and Energy Technology (i-MEET) at the Friedrich Alexander University Erlangen-Nuernberg under the supervision of prof. Christoph J. Brabec. From October 2015, he was a postdoctoral fellow in the group of Prof. Brabec in i-MEET. He joined Wuhan University in 2017. His major research interest is in the physics and chemistry of organic photovoltaic materials, and photovoltaic device physics and engineering.
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Shi, M., Wang, T., Sun, R. et al. Remove the water-induced traps toward improved performance in organic solar cells. Sci. China Mater. 64, 2629–2644 (2021). https://doi.org/10.1007/s40843-021-1703-4
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DOI: https://doi.org/10.1007/s40843-021-1703-4