Abstract
In this study, a porous inorganic/organic (ZnO/PEIE, where PEIE is polyethylenimine ethoxylated) (P-ZnO) hybrid material has been developed and adopted in the inverted organic solar cells (OSCs). The P-ZnO serving as the electron transport layer (ETL) not only presents an ameliorative work function, but also forms the cratered surface with increased ohmic contact area, revealing suppressed charge recombination and enhanced charge extraction in devices. Particularly, P-ZnO-based OSCs show improved light trapping in the active layer compared with ZnO-based ones. The universality of P-ZnO serving as ETL for efficient OSCs is verified on three photovoltaic systems of PBDB-T/DTPPSe-2F, PM6/Y6, and PTB7-Th/PC71BM. The enhancements of 8% in power conversion efficiency (PCE) can be achieved in the state-of-the-art OSCs based on PBDB-T/DTPPSe-2F, PM6/Y6, and PTB7-Th/PC71BM, delivering PCEs of 14.78%, 16.57%, and 9.85%, respectively. Furthermore, a promising PCE of 14.13% under air-processed condition can be achieved for PZnO/PBDB-T/DTPPSe-2F-based OSC, which is among the highest efficiencies reported for air-processed OSCs in the literature. And the P-ZnO/PBDB-T/DTPPSe-2F-based device also presents superior long-term storage stability whether in nitrogen or ambient air-condition without encapsulation, which can maintain over 85% of its initial efficiency. Our results demonstrate the great potential of the porous hybrid PZnO as ETL for constructing high-performance and air-stable OSCs.
摘要
在本工作中, 我们制备了一种多孔的有机/无机复合电子传 输层(P-ZnO), 并将其成功用于反向有机太阳能电池中. P-ZnO不 仅拥有适宜的功函, 且可形成较大欧姆接触面积的独特表面, 有利 于器件中的电荷提取. 与ZnO基器件相比, P-ZnO基器件的活性层 具有增强的光陷阱效应. 在PBDB-T/DTPPSe-2F, PM6/Y6和PTB7- Th/PC71BM三个活性层体系中, 基于P-ZnO的器件都可实现8%增 幅的效率提升. 尤其是P-ZnO/PBDB-T/DTPPSe-2F的未封装器件 无论在氮气还是空气氛围下, 均表现出良好的长期稳定性. 在空气 中制备的P-ZnO/PBDB-T/DTPPSe-2F器件仍可实现14.13%的高效 率, 这是目前文献报道的空气氛围制备有机太阳能电池的最高效 率之一. 实验结果表明, P-ZnO作为电子传输层在构建高性能和空 气稳定的有机太阳能电池方面具有巨大的应用潜力.
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Acknowledgements
This work was supported by the National Natural Science Foundation of China (21905137) and the Natural Science Foundation of Jiangsu Province (BK20180496).
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Yu J and Qu S conceived and designed the experiments; Cao J provided the acceptor DTPPSe-2F; Wang H and Guang S performed the morphology characterizations; Liu X performed the optical simulations; Yu J and Tang W directed the project. All authors contributed to the general discussion.
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Supporting data are available in the online version of the paper.
Shenya Qu received her BSc degree from Nanjing Forest University. She has been pursuing her postgraduate degree in Nanjing University of Science and Technology since 2018. Her research interests focus on the device fabrication and optical optimization for interlayer modification in organic solar cells.
Jiangsheng Yu received his PhD degree in 2017 from Nanjing University of Science and Technology and the University of Washington. Then, he joined MIIT Key Laboratory of Advanced Solid Laser in Nanjing University of Science and Technology. His research mainly focuses on photovoltaic material development and device engineering on organic solar cells.
Weihua Tang has been a professor in Nanjing University of Science and Technology since 2009. He received his PhD degree in chemistry from National University of Singapore. His research interests mainly focus on molecular design of conjugated materials and device optimization for organic/perovskite solar cells and energy storage systems.
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Qu, S., Yu, J., Cao, J. et al. Highly efficient organic solar cells enabled by a porous ZnO/PEIE electron transport layer with enhanced light trapping. Sci. China Mater. 64, 808–819 (2021). https://doi.org/10.1007/s40843-020-1508-7
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DOI: https://doi.org/10.1007/s40843-020-1508-7