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He D, Li Y, Zhao F, Lin Y. Trap suppression in ordered organic photovoltaic heterojunctions. Chem Commun (Camb) 2024; 60:364-373. [PMID: 38099599 DOI: 10.1039/d3cc05559k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
The high trap density (generally 1016-1018 cm-3) in organic solar cells (OSCs) brings about the localization of charge carriers and reduced charge carrier lifetime, mainly due to the weak intermolecular interactions of organic semiconductors resulting in their relatively poor crystallinity, which leads to low charge carrier mobilities and intense non-radiative recombination, thus impeding the further improvement of power conversion efficiencies (PCEs). Therefore, trap suppression is crucial to boost the performance of OSCs, and improving the crystallinity of donor/acceptor materials and enhancing the molecular order in devices can contribute to the trap suppression in OSCs. In this feature article, we summarize the recent advances of trap suppression in OSCs by material design and device engineering, and further outline possible development directions for trap suppression to enhance PCEs of OSCs.
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Affiliation(s)
- Dan He
- College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, P. R. China.
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China.
| | - Yawen Li
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China.
- University of Chinese Academy of Sciences, Beijing 100190, P. R. China
| | - Fuwen Zhao
- College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, P. R. China.
| | - Yuze Lin
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China.
- University of Chinese Academy of Sciences, Beijing 100190, P. R. China
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Luo D, Jiang Z, Shan C, Li L, Duan C, Liu Q, Wang Z, Wang K, Xu B, Kyaw AKK. Simultaneous Tuning of Alkyl Chains and End Groups in Non-fused Ring Electron Acceptors for Efficient and Stable Organic Solar Cells. ACS APPLIED MATERIALS & INTERFACES 2022; 14:24374-24385. [PMID: 35580336 DOI: 10.1021/acsami.2c03723] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Fine-tuning the alkyl chains and end groups of non-fused ring electron acceptors (NFREAs) plays vital roles in the promotion of charge transfer (CT) and power conversion efficiency (PCE). In this work, we developed a series of A-D-A'-D-A-type NFREAs, which possess the same terminals (A), the cyclopentadithiophene unit (D), and the thieno[3,4-c]pyrrole-4,6-dione (A'). Despite the subtle difference in side chains and halogenated end groups, the six acceptors exhibit a considerable difference in the efficiency and device stability of the organic solar cells (OSCs). Among the molecules, chlorinated NFREAs show a broader light absorption than the fluorinated ones do. Compared with C8C8-4F (1-octylnonyl and fluorination) and C6C4-4Cl (2-butyloctyl and chlorination), C8C8-4Cl (1-octylnonyl and chlorination) exhibits a lower highest occupied molecular orbital level, higher electron mobility, and denser molecular packing. The OSCs based on PM6:C8C8-4Cl yield the best PCE of 14.11%, which is attributed to the faster charge transport, high miscibility, and preferable morphology. Moreover, the PM6:C8C8-4Cl devices retain 91.1% of the initial PCE after being placed in air with 67% relative humidity for 50 days. This work shows that the simultaneous optimization of side chains and end groups facilitates the CT and improves the stability in the OSCs, offering a novel view into the molecular design of A-D-A'-D-A-type NFREAs.
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Affiliation(s)
- Dou Luo
- Guangdong University Key Laboratory for Advanced Quantum Dot Displays and Lighting, Department of Electrical & Electronic Engineering, Southern University of Science and Technology, Shenzhen 518055, China
| | - Zhengyan Jiang
- Department of Materials Science and Engineering and Shenzhen Engineering Research and Development Center for Flexible Solar Cells, Southern University of Science and Technology, Shenzhen 518055, China
| | - Chengwei Shan
- Guangdong University Key Laboratory for Advanced Quantum Dot Displays and Lighting, Department of Electrical & Electronic Engineering, Southern University of Science and Technology, Shenzhen 518055, China
| | - Lanqing Li
- School of Biotechnology and Health Sciences, Wuyi University, Jiangmen 529020, China
| | - Chenghao Duan
- Guangdong Provincial Key Laboratory of Solid Wastes Pollution Control and Recycling, State Key Laboratory of Luminescent Materials and Devices, School of Environment and Energy, South China University of Technology, Guangzhou 510000, China
| | - Qian Liu
- Guangdong University Key Laboratory for Advanced Quantum Dot Displays and Lighting, Department of Electrical & Electronic Engineering, Southern University of Science and Technology, Shenzhen 518055, China
| | - Zhaojin Wang
- Guangdong University Key Laboratory for Advanced Quantum Dot Displays and Lighting, Department of Electrical & Electronic Engineering, Southern University of Science and Technology, Shenzhen 518055, China
| | - Kai Wang
- Guangdong University Key Laboratory for Advanced Quantum Dot Displays and Lighting, Department of Electrical & Electronic Engineering, Southern University of Science and Technology, Shenzhen 518055, China
| | - Baomin Xu
- Department of Materials Science and Engineering and Shenzhen Engineering Research and Development Center for Flexible Solar Cells, Southern University of Science and Technology, Shenzhen 518055, China
| | - Aung Ko Ko Kyaw
- Guangdong University Key Laboratory for Advanced Quantum Dot Displays and Lighting, Department of Electrical & Electronic Engineering, Southern University of Science and Technology, Shenzhen 518055, China
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Li P, Chen L, Hu X, He L, Jiang Z, Luo M, Huang H, Yuan W, He Y. Effective Double Electron Transport Layer Inducing Crystallization of Active Layer for Improving the Performance of Organic Solar Cells. NANOMATERIALS (BASEL, SWITZERLAND) 2021; 12:15. [PMID: 35009965 PMCID: PMC8746582 DOI: 10.3390/nano12010015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 12/08/2021] [Accepted: 12/14/2021] [Indexed: 06/14/2023]
Abstract
Interface modification plays an important role in enhancing the photoelectric conversion efficiency and stability of organic solar cells. In this work, alkali metal lithium chloride (LiCl) was introduced between indium tin oxide and polyethyleneimine ethoxylate (PEIE) to prepare a double-layer electron transport layer. Results show that the introduction of LiCl has dual functions. The first function is that LiCl can enhance conductivity, thereby facilitating charge collection. The second function is that the double-layer electron transport layer based on LiCl can induce the crystallization of active layer, thereby enhancing charge transport. Devices with LiCl/PEIE double layer achieve a high power conversion efficiency (PCE) of 3.84%, which is 21.5% higher than that of pristine devices (the PCE of pristine devices with pure PEIE interface layer is 3.16%).
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Affiliation(s)
- Ping Li
- School of Physics and Electronic Science, Zunyi Normal University, Zunyi 563006, China; (X.H.); (L.H.); (Z.J.); (M.L.); (H.H.); (Y.H.)
| | - Lijia Chen
- College of Physics and Electronic Engineering, Chongqing Normal University, Chongqing 401331, China;
| | - Xiaoyan Hu
- School of Physics and Electronic Science, Zunyi Normal University, Zunyi 563006, China; (X.H.); (L.H.); (Z.J.); (M.L.); (H.H.); (Y.H.)
| | - Lirong He
- School of Physics and Electronic Science, Zunyi Normal University, Zunyi 563006, China; (X.H.); (L.H.); (Z.J.); (M.L.); (H.H.); (Y.H.)
| | - Zezhuan Jiang
- School of Physics and Electronic Science, Zunyi Normal University, Zunyi 563006, China; (X.H.); (L.H.); (Z.J.); (M.L.); (H.H.); (Y.H.)
| | - Minghao Luo
- School of Physics and Electronic Science, Zunyi Normal University, Zunyi 563006, China; (X.H.); (L.H.); (Z.J.); (M.L.); (H.H.); (Y.H.)
| | - Haishen Huang
- School of Physics and Electronic Science, Zunyi Normal University, Zunyi 563006, China; (X.H.); (L.H.); (Z.J.); (M.L.); (H.H.); (Y.H.)
| | - Wei Yuan
- Department of Rail Transportation Engineering, GuiZhou Communication Polythechnic, Guiyang 551400, China;
| | - Yinghu He
- School of Physics and Electronic Science, Zunyi Normal University, Zunyi 563006, China; (X.H.); (L.H.); (Z.J.); (M.L.); (H.H.); (Y.H.)
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Su D, Li K, Liu W, Zhang W, Li X, Wu Y, Shen F, Huo S, Fu H, Zhan C. High-Performance Ternary Polymer Solar Cells Enabled by a New Narrow Bandgap Nonfullerene Small Molecule Acceptor with a Higher LUMO Level. Macromol Rapid Commun 2020; 41:e2000393. [PMID: 33089640 DOI: 10.1002/marc.202000393] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Revised: 10/04/2020] [Indexed: 11/06/2022]
Abstract
Obtaining a large open-circuit voltage (VOC ) and high short-circuit current density (JSC ) simultaneously is important in improving power conversion efficiency (PCE) of organic photovoltaics. The ternary strategy with using a higher lowest unoccupied molecular orbital (LUMO) level nonfullerene acceptor (NFA) guest can achieve increased VOC , yet JSC is decreased or maintained, so it's still a challenge to offer increased VOC and JSC values concurrently via the newly presented VOC -increased ternary strategy. To overcome this issue, a new narrow bandgap NFA TT-S-4F is reported by introducing 3,6-dimethoxylthieno[3,2-b]thiophene (TT) as π-spacers to connect electron-rich core with terminal groups, so as to upshift the LUMO level and extend π-system. When adding 10% TT-S-4F into binary system based on PTB7-Th:IEICO-4F, the higher-LUMO-level of TT-S-4F, the increased charge mobilities, the reduced trap-assisted combination loss, and a finer nanofiber structure and increased phase separation size are obtained, which simultaneously promotes JSC , VOC , and fill factor (FF), thus obtaining an optimal PCE (12.5% vs 11.5%). This work illustrates that an extending conjugated backbone with large π-spacers and inclusion of alkylthiophenyl side-chains is a concept to synthesize NFA guests for use on the VOC -increased ternary strategy that enables to realize simultaneously increased JSC , VOC , and FF.
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Affiliation(s)
- Dan Su
- College of Chemistry and Environmental Science, Hebei University, Baoding, Hebei Province, 071002, China
| | - Kun Li
- Beijing Key Laboratory for Optical Materials and Photonic Devices, Department of Chemistry, Capital Normal University, Beijing, 100048, China
| | - Wanru Liu
- College of Chemistry and Environmental Science, Hebei University, Baoding, Hebei Province, 071002, China
| | - Weichao Zhang
- Key Laboratory of Excitonic Materials Chemistry and Devices (EMC&D), College of Chemistry and Environmental Science, Inner Mongolia Normal University, Huhhot, 010022, China
| | - Xiaofang Li
- College of Chemistry and Environmental Science, Hebei University, Baoding, Hebei Province, 071002, China
| | - Yishi Wu
- Beijing Key Laboratory for Optical Materials and Photonic Devices, Department of Chemistry, Capital Normal University, Beijing, 100048, China
| | - Fugang Shen
- College of Chemistry and Environmental Science, Hebei University, Baoding, Hebei Province, 071002, China
| | - Shuying Huo
- College of Chemistry and Environmental Science, Hebei University, Baoding, Hebei Province, 071002, China
| | - Hongbing Fu
- Beijing Key Laboratory for Optical Materials and Photonic Devices, Department of Chemistry, Capital Normal University, Beijing, 100048, China
| | - Chuanlang Zhan
- Key Laboratory of Excitonic Materials Chemistry and Devices (EMC&D), College of Chemistry and Environmental Science, Inner Mongolia Normal University, Huhhot, 010022, China
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