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Cai G, Li Y, Fu Y, Yang H, Mei L, Nie Z, Li T, Liu H, Ke Y, Wang XL, Brédas JL, Tang MC, Chen X, Zhan X, Lu X. Deuteration-enhanced neutron contrasts to probe amorphous domain sizes in organic photovoltaic bulk heterojunction films. Nat Commun 2024; 15:2784. [PMID: 38555349 PMCID: PMC10981694 DOI: 10.1038/s41467-024-47052-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Accepted: 03/17/2024] [Indexed: 04/02/2024] Open
Abstract
An organic photovoltaic bulk heterojunction comprises of a mixture of donor and acceptor materials, forming a semi-crystalline thin film with both crystalline and amorphous domains. Domain sizes critically impact the device performance; however, conventional X-ray scattering techniques cannot detect the contrast between donor and acceptor materials within the amorphous intermixing regions. In this study, we employ neutron scattering and targeted deuteration of acceptor materials to enhance the scattering contrast by nearly one order of magnitude. Remarkably, the PM6:deuterated Y6 system reveals a new length scale, indicating short-range aggregation of Y6 molecules in the amorphous intermixing regions. All-atom molecular dynamics simulations confirm that this short-range aggregation is an inherent morphological advantage of Y6 which effectively assists charge extraction and suppresses charge recombination as shown by capacitance spectroscopy. Our findings uncover the amorphous nanomorphology of organic photovoltaic thin films, providing crucial insights into the morphology-driven device performance.
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Affiliation(s)
- Guilong Cai
- Department of Physics, The Chinese University of Hong Kong, Hong Kong, China
- Beijing Key Laboratory of Ionic Liquids Clean Process, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, China
| | - Yuhao Li
- Department of Physics, The Chinese University of Hong Kong, Hong Kong, China.
- Spallation Neutron Source Science Center, Dongguan, 523803, China.
- Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 10049, China.
| | - Yuang Fu
- Department of Physics, The Chinese University of Hong Kong, Hong Kong, China
| | - Hua Yang
- Spallation Neutron Source Science Center, Dongguan, 523803, China
- Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 10049, China
| | - Le Mei
- Department of Materials Science and Engineering, City University of Hong Kong, Hong Kong, China
| | - Zhaoyang Nie
- Institute of Materials Research, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, China
| | - Tengfei Li
- School of Materials Science and Engineering, Peking University, Beijing, China
| | - Heng Liu
- Department of Physics, The Chinese University of Hong Kong, Hong Kong, China
| | - Yubin Ke
- Spallation Neutron Source Science Center, Dongguan, 523803, China
- Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 10049, China
| | - Xun-Li Wang
- Department of Physics and Center for Neutron Scattering, City University of Hong Kong, Hong Kong, China
- Hong Kong Institute for Advanced Study, City University of Hong Kong, Hong Kong, China
| | - Jean-Luc Brédas
- Department of Chemistry and Biochemistry, The University of Arizona, Tucson, Arizona, 85721-0041, USA
| | - Man-Chung Tang
- Institute of Materials Research, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, China
| | - Xiankai Chen
- Department of Materials Science and Engineering, City University of Hong Kong, Hong Kong, China
| | - Xiaowei Zhan
- School of Materials Science and Engineering, Peking University, Beijing, China.
| | - Xinhui Lu
- Department of Physics, The Chinese University of Hong Kong, Hong Kong, China.
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Wang R, Lüer L, Langner S, Heumueller T, Forberich K, Zhang H, Hauch J, Li N, Brabec CJ. Understanding the Microstructure Formation of Polymer Films by Spontaneous Solution Spreading Coating with a High-Throughput Engineering Platform. CHEMSUSCHEM 2021; 14:3590-3598. [PMID: 34236142 PMCID: PMC8518985 DOI: 10.1002/cssc.202100927] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Revised: 06/25/2021] [Indexed: 05/26/2023]
Abstract
An important step of the great achievement of organic solar cells in power conversion efficiency is the development of low-band gap polymer donors, PBDB-T derivatives, which present interesting aggregation effects dominating the device performance. The aggregation of polymers can be manipulated by a series of variables from a materials design and processing conditions perspective; however, optimization of film quality is a time- and energy-consuming work. Here, we introduce a robot-based high-throughput platform (HTP) that is offering automated film preparation and optical spectroscopy thin-film characterization in combination with an analysis algorithm. PM6 films are prepared by the so-called spontaneous film spreading (SFS) process, where a polymer solution is coated on a water surface. Automated acquisition of UV/Vis and photoluminescence (PL) spectra and automated extraction of morphological features is coupled to Gaussian Process Regression to exploit available experimental evidence for morphology optimization but also for hypothesis formulation and testing with respect to the underlying physical principles. The integrated spectral modeling workflow yields quantitative microstructure information by distinguishing amorphous from ordered phases and assesses the extension of amorphous versus the ordered domains. This research provides an easy to use methodology to analyze the exciton coherence length in conjugated semiconductors and will allow to optimize exciton splitting in thin film organic semiconductor layers as a function of processing.
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Affiliation(s)
- Rong Wang
- Institute of Materials for Electronics and Energy Technology (i-MEET)Friedrich-Alexander-Universität Erlangen-NürnbergMartensstrasse 791058ErlangenGermany
- Erlangen Graduate School in Advanced Optical Technologies (SAOT)Paul-Gordan-Straße 691052ErlangenGermany
| | - Larry Lüer
- Institute of Materials for Electronics and Energy Technology (i-MEET)Friedrich-Alexander-Universität Erlangen-NürnbergMartensstrasse 791058ErlangenGermany
| | - Stefan Langner
- Institute of Materials for Electronics and Energy Technology (i-MEET)Friedrich-Alexander-Universität Erlangen-NürnbergMartensstrasse 791058ErlangenGermany
- Helmholtz Institute Erlangen-Nürnberg for Renewable Energy (IEK-11)Immerwahrstrasse 291058ErlangenGermany
| | - Thomas Heumueller
- Institute of Materials for Electronics and Energy Technology (i-MEET)Friedrich-Alexander-Universität Erlangen-NürnbergMartensstrasse 791058ErlangenGermany
- Helmholtz Institute Erlangen-Nürnberg for Renewable Energy (IEK-11)Immerwahrstrasse 291058ErlangenGermany
| | - Karen Forberich
- Institute of Materials for Electronics and Energy Technology (i-MEET)Friedrich-Alexander-Universität Erlangen-NürnbergMartensstrasse 791058ErlangenGermany
- Helmholtz Institute Erlangen-Nürnberg for Renewable Energy (IEK-11)Immerwahrstrasse 291058ErlangenGermany
| | - Heyi Zhang
- Institute of Materials for Electronics and Energy Technology (i-MEET)Friedrich-Alexander-Universität Erlangen-NürnbergMartensstrasse 791058ErlangenGermany
- Erlangen Graduate School in Advanced Optical Technologies (SAOT)Paul-Gordan-Straße 691052ErlangenGermany
| | - Jens Hauch
- Institute of Materials for Electronics and Energy Technology (i-MEET)Friedrich-Alexander-Universität Erlangen-NürnbergMartensstrasse 791058ErlangenGermany
- Helmholtz Institute Erlangen-Nürnberg for Renewable Energy (IEK-11)Immerwahrstrasse 291058ErlangenGermany
| | - Ning Li
- Institute of Materials for Electronics and Energy Technology (i-MEET)Friedrich-Alexander-Universität Erlangen-NürnbergMartensstrasse 791058ErlangenGermany
- Helmholtz Institute Erlangen-Nürnberg for Renewable Energy (IEK-11)Immerwahrstrasse 291058ErlangenGermany
- National Engineering Research Center for Advanced Polymer Processing TechnologyZhengzhou University450002ZhengzhouP. R. China
| | - Christoph J. Brabec
- Institute of Materials for Electronics and Energy Technology (i-MEET)Friedrich-Alexander-Universität Erlangen-NürnbergMartensstrasse 791058ErlangenGermany
- Helmholtz Institute Erlangen-Nürnberg for Renewable Energy (IEK-11)Immerwahrstrasse 291058ErlangenGermany
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