Uncovering the out-of-plane nanomorphology of organic photovoltaic bulk heterojunction by GTSAXS

Xinxin Xia; Tsz-Ki Lau; Xuyun Guo; Yuhao Li; Minchao Qin; Kuan Liu; Zeng Chen; Xiaozhi Zhan; Yiqun Xiao; Pok Fung Chan; Heng Liu; Luhang Xu; Guilong Cai; Na Li; Haiming Zhu; Gang Li; Ye Zhu; Tao Zhu; Xiaowei Zhan; Xun-Li Wang; Xinhui Lu

doi:10.1038/s41467-021-26510-6

Uncovering the out-of-plane nanomorphology of organic photovoltaic bulk heterojunction by GTSAXS

Nat Commun. 2021 Oct 28;12(1):6226. doi: 10.1038/s41467-021-26510-6.

Authors

Xinxin Xia^#¹, Tsz-Ki Lau^#¹, Xuyun Guo², Yuhao Li¹, Minchao Qin¹, Kuan Liu³, Zeng Chen⁴, Xiaozhi Zhan^{5

6}, Yiqun Xiao¹, Pok Fung Chan¹, Heng Liu¹, Luhang Xu¹, Guilong Cai¹, Na Li⁷, Haiming Zhu⁴, Gang Li³, Ye Zhu², Tao Zhu⁸, Xiaowei Zhan⁹, Xun-Li Wang¹⁰, Xinhui Lu¹¹

Affiliations

¹ Department of Physics, The Chinese University of Hong Kong, New Territories, Hong Kong, 999077, China.
² Department of Applied Physics, Research Institute for Smart Energy, The Hong Kong Polytechnic University, Hung Hom, Hong Kong, China.
³ Department of Electronic and Information Engineering, Research Institute for Smart Energy (RISE), The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China.
⁴ Center for Chemistry of High-Performance & Novel Materials, Department of Chemistry, Zhejiang University, Hangzhou, 310027, Zhejiang, China.
⁵ Spallation Neutron Source Science Center, Dongguan, 523803, China.
⁶ Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, China.
⁷ National Facility for Protein Science in Shanghai, Zhangjiang Laboratory, Shanghai Advanced Research Institute, Chinese Academy of Science, No.333, Haike Road, Shanghai, 201204, People's Republic of China.
⁸ Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China.
⁹ School of Materials Science and Engineering, Peking University, Beijing, 100871, China.
¹⁰ Department of Physics and Center for Neutron Scattering, City University of Hong Kong, Kowloon, Hong Kong, China.
¹¹ Department of Physics, The Chinese University of Hong Kong, New Territories, Hong Kong, 999077, China. xinhui.lu@cuhk.edu.hk.

^# Contributed equally.

Abstract

The bulk morphology of the active layer of organic solar cells (OSCs) is known to be crucial to the device performance. The thin film device structure breaks the symmetry into the in-plane direction and out-of-plane direction with respect to the substrate, leading to an intrinsic anisotropy in the bulk morphology. However, the characterization of out-of-plane nanomorphology within the active layer remains a grand challenge. Here, we utilized an X-ray scattering technique, Grazing-incident Transmission Small-angle X-ray Scattering (GTSAXS), to uncover this new morphology dimension. This technique was implemented on the model systems based on fullerene derivative (P3HT:PC₇₁BM) and non-fullerene systems (PBDBT:ITIC, PM6:Y6), which demonstrated the successful extraction of the quantitative out-of-plane acceptor domain size of OSC systems. The detected in-plane and out-of-plane domain sizes show strong correlations with the device performance, particularly in terms of exciton dissociation and charge transfer. With the help of GTSAXS, one could obtain a more fundamental perception about the three-dimensional nanomorphology and new angles for morphology control strategies towards highly efficient photovoltaic devices.

Abstract

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