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Yan L, Liang Z, Si J, Gong P, Wang Y, Liu X, Tong J, Li J, Hou X. Ultrafast Kinetics of Chlorinated Polymer Donors: A Faster Excitonic Dissociation Path. ACS APPLIED MATERIALS & INTERFACES 2022; 14:6945-6957. [PMID: 35081710 DOI: 10.1021/acsami.1c24348] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Halogen-substituted donor/acceptor materials are widely regarded as a promising strategy toward improved power-conversion efficiencies (PCEs) in polymer solar cells (PSCs). A chlorinated polymer donor, PClBTA-PS, and its non-chlorinated analogue, PBTA-PS, are synthesized. The PClBTA-PS-based devices show significant enhancements in terms of open-circuit voltage (VOC = 0.82 V) and fill factor (FF = 76.20%). In addition, a PCE of 13.20% is obtained, which is significantly higher than that for the PBTA-PS-based devices (PCE = 7.63%). Grazing incident wide-angle X-ray scattering shows that the chlorinated polymer enables better π-π stacking in both pure and blend films. DFT and TD-DFT calculations as well as ultrafast photophysics measurements indicate that chlorinated PClBTA-PS has a smaller bonding energy and a longer spontaneous-emission lifetime. The results also reveal that the charge-transfer-state excitons in PClBTA-PS:IT4Cl blend films split into the charge-separated (CS) state via a faster dissociation path, which produces a higher yield of the CS state. Overall, this study provides a deeper understanding of how a halogen-substituted polymer can improve PSCs in the future.
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Affiliation(s)
- Lihe Yan
- Key Laboratory for Physical Electronics and Devices of the Ministry of Education & Shaanxi Key Lab of Photonic Technique for Information, School of Electronics Science & Engineering, Faculty of Electronic and Information Engineering, Xi'an Jiaotong University, Xi'an 710049, China
| | - Zezhou Liang
- Key Laboratory for Physical Electronics and Devices of the Ministry of Education & Shaanxi Key Lab of Photonic Technique for Information, School of Electronics Science & Engineering, Faculty of Electronic and Information Engineering, Xi'an Jiaotong University, Xi'an 710049, China
| | - Jinhai Si
- Key Laboratory for Physical Electronics and Devices of the Ministry of Education & Shaanxi Key Lab of Photonic Technique for Information, School of Electronics Science & Engineering, Faculty of Electronic and Information Engineering, Xi'an Jiaotong University, Xi'an 710049, China
| | - Pingping Gong
- School of Materials Science and Engineering, Gansu Provincial Engineering Research Center for Organic Semiconductor Materials and Application Technology, Lanzhou Jiaotong University, Lanzhou 730070, China
| | - Yufei Wang
- Siyuan Laboratory, Guangzhou Key Laboratory of Vacuum Coating Technologies and New Energy Materials, Department of Physics, Jinan University, Guangzhou 510632, China
| | - Xingpeng Liu
- School of Materials Science and Engineering, Gansu Provincial Engineering Research Center for Organic Semiconductor Materials and Application Technology, Lanzhou Jiaotong University, Lanzhou 730070, China
| | - Junfeng Tong
- School of Materials Science and Engineering, Gansu Provincial Engineering Research Center for Organic Semiconductor Materials and Application Technology, Lanzhou Jiaotong University, Lanzhou 730070, China
| | - Jianfeng Li
- School of Materials Science and Engineering, Gansu Provincial Engineering Research Center for Organic Semiconductor Materials and Application Technology, Lanzhou Jiaotong University, Lanzhou 730070, China
| | - Xun Hou
- Key Laboratory for Physical Electronics and Devices of the Ministry of Education & Shaanxi Key Lab of Photonic Technique for Information, School of Electronics Science & Engineering, Faculty of Electronic and Information Engineering, Xi'an Jiaotong University, Xi'an 710049, China
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Wang H, Nakagawa T, Zhang MM, Ogumi K, Yang S, Matsuo Y. High-yielding Pd 2(dba) 3·C 6H 6-based four-fold Sonogashira coupling with selenophene-conjugated magnesium tetraethynylporphyrin for organic solar cells. RSC Adv 2019; 9:32562-32572. [PMID: 35529715 PMCID: PMC9073152 DOI: 10.1039/c9ra07393k] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2019] [Accepted: 09/25/2019] [Indexed: 01/24/2023] Open
Abstract
A catalytic system using Pd2(dba)3·(C6H6)/PPh3/CuI for Sonogashira coupling was demonstrated to synthesize a selenophene-conjugated magnesium tetraethynylporphyrin Mg-TEP-(Se-DPP)4 (2a). The catalytic system enabled four-fold cross-coupling of the four terminal alkynes of magnesium tetraethynylporphyrin with bromoselenophene-tethered diketopyrrolopyrroles (DPPs) to produce the desired star-shaped 2a in 80% yield. This molecule shows higher solubility in organic solvents, more efficient visible and near-infrared region absorption, and a narrower band gap compared with reference thiophene-conjugated congeners. Two strategies, namely, selenium substitution and end-capping, were investigated to optimize bulk heterojunction structures in the active layers of organic solar cells. The optimized device based on 2a:PC61BM exhibited the highest PCE of 6.09% among the tested devices after solvent vapor annealing, owing to efficient exciton dissociation, balanced carrier mobility, and suppressed carrier recombination in the film's ordered morphology.
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Affiliation(s)
- Huan Wang
- Hefei National Laboratory for Physical Science at the Microscale, University of Science and Technology of China Hefei Anhui 230026 China
| | - Takafumi Nakagawa
- Department of Mechanical Engineering, School of Engineering, The University of Tokyo 7-3-1 Hongo, Bunkyo-ku Tokyo 113-8656 Japan
| | - Meng-Meng Zhang
- Department of Materials Science and Engineering, CAS Key Laboratory of Materials for Energy Conversion, University of Science and Technology of China Hefei Anhui 230026 China
| | - Keisuke Ogumi
- Tokyo Metropolitan Industrial Technology Research Institute 2-4-10 Aomi, Koto-ku Tokyo 135-0064 Japan
| | - Shangfeng Yang
- Hefei National Laboratory for Physical Science at the Microscale, University of Science and Technology of China Hefei Anhui 230026 China
- Department of Materials Science and Engineering, CAS Key Laboratory of Materials for Energy Conversion, University of Science and Technology of China Hefei Anhui 230026 China
| | - Yutaka Matsuo
- Hefei National Laboratory for Physical Science at the Microscale, University of Science and Technology of China Hefei Anhui 230026 China
- Department of Mechanical Engineering, School of Engineering, The University of Tokyo 7-3-1 Hongo, Bunkyo-ku Tokyo 113-8656 Japan
- Institute of Materials Innovation, Institutes for Innovation for Future Society, Nagoya University Furo-cho, Chikusa-ku Nagoya 464-8603 Japan
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Deng W, Gao K, Yan J, Liang Q, Xie Y, He Z, Wu H, Peng X, Cao Y. Origin of Reduced Open-Circuit Voltage in Highly Efficient Small-Molecule-Based Solar Cells upon Solvent Vapor Annealing. ACS APPLIED MATERIALS & INTERFACES 2018; 10:8141-8147. [PMID: 29411601 DOI: 10.1021/acsami.7b17546] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
In this study, we demonstrate that remarkably reduced open-circuit voltage in highly efficient organic solar cells (OSCs) from a blend of phenyl-C61-butyric acid methyl ester and a recently developed conjugated small molecule (DPPEZnP-THD) upon solvent vapor annealing (SVA) is due to two independent sources: increased radiative recombination and increased nonradiative recombination. Through the measurements of electroluminescence due to the emission of the charge-transfer state and photovoltaic external quantum efficiency measurement, we can quantify that the open-circuit voltage losses in a device with SVA due to the radiative recombination and nonradiative recombination are 0.23 and 0.31 V, respectively, which are 0.04 and 0.07 V higher than those of the as-cast device. Despite of the reduced open-circuit voltage, the device with SVA exhibited enhanced dissociation of charge-transfer excitons, leading to an improved short-circuit current density and a remarkable power conversion efficiency (PCE) of 9.41%, one of the best for solution-processed OSCs based on small-molecule donor materials. Our study also clearly shows that removing the nonradiative recombination pathways and/or suppressing energetic disorder in the active layer would result in more long-lived charge carriers and enhanced open-circuit voltage, which are prerequisites for further improving the PCE.
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Affiliation(s)
- Wanyuan Deng
- Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices , South China University of Technology , Guangzhou 510640 , P. R. China
| | - Ke Gao
- Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices , South China University of Technology , Guangzhou 510640 , P. R. China
| | - Jun Yan
- Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices , South China University of Technology , Guangzhou 510640 , P. R. China
| | - Quanbin Liang
- Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices , South China University of Technology , Guangzhou 510640 , P. R. China
| | - Yuan Xie
- Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices , South China University of Technology , Guangzhou 510640 , P. R. China
| | - Zhicai He
- Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices , South China University of Technology , Guangzhou 510640 , P. R. China
| | - Hongbin Wu
- Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices , South China University of Technology , Guangzhou 510640 , P. R. China
| | - Xiaobin Peng
- Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices , South China University of Technology , Guangzhou 510640 , P. R. China
| | - Yong Cao
- Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices , South China University of Technology , Guangzhou 510640 , P. R. China
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