Fine‐Tuning the Photovoltaic Performance of Organic Solar Cells by Collaborative Optimization of Structural Isomerism and Halogen Atom
Fused‐ring acceptors based on an electron‐deficient core, such as Y6, have become a successful strategy in bulk heterojunction (BHJ) organic solar cells (OSCs) for high power conversion efficiencies (PCEs). Here, five fused‐ring electron acceptors (Y9, Y9‐2F, Y9‐2Cl, i‐Y9‐2F, i‐Y9‐2Cl) are synthesiz...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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Wiley-VCH
2022-01-01
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| Series: | Advanced Energy & Sustainability Research |
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| Online Access: | https://doi.org/10.1002/aesr.202100138 |
| _version_ | 1818973462295740416 |
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| author | Zhe Li Na Zhang Honggang Chen Hongjian Peng Yingping Zou |
| author_facet | Zhe Li Na Zhang Honggang Chen Hongjian Peng Yingping Zou |
| author_sort | Zhe Li |
| collection | DOAJ |
| description | Fused‐ring acceptors based on an electron‐deficient core, such as Y6, have become a successful strategy in bulk heterojunction (BHJ) organic solar cells (OSCs) for high power conversion efficiencies (PCEs). Here, five fused‐ring electron acceptors (Y9, Y9‐2F, Y9‐2Cl, i‐Y9‐2F, i‐Y9‐2Cl) are synthesized using fused dithienothiophen[3,2‐b]pyrrolobenzotriazole and halogenated 1,1‐dicyanomethylene‐3‐indanone (IC) to investigate the effect of end‐group (EG) halogenation and structural isomerism on BHJ photovoltaic performance. Due to the strong electronegativity of halogens, all the acceptors with halogenated terminal units possess redshifted absorption spectra and deeper frontier energy levels compared with Y9. Different from asymmetric molecules i‐Y9‐2F and i‐Y9‐2Cl, Y9‐2F and Y9‐2Cl exhibit slightly lower bandgaps. Moreover, the devices based on fluorinated acceptors show more efficient charge collection, obtaining relatively high short‐circuit current density (J sc) and fill factor (FF). The lowest unoccupied molecular orbital energy levels of halogenated acceptors are similar. As a result, OSCs based on poly[(2,6‐(4,8‐bis(5‐(2‐ethylhexyl)thiophen‐2‐yl)‐benzo[1,2‐b:4,5‐b′]dithio‐phene))‐alt‐(5,5‐ (1′,3′‐di‐2‐thienyl‐5′,7′‐bis(2‐ethyl‐hexyl) benzo[1′,2′‐c:4′,5′‐c′]dithiophene‐4,8‐dione))] (PBDB‐T):Y9‐2F obtain more balanced J sc and open‐circuit voltage (V oc), and thus an optimal PCE of 15.49% is demonstrated with a V oc of 0.84 V, J sc of 26.30 mA cm−2, and FF of 70.05%. |
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| id | doaj.art-b154e60160454b028cd3e766062bf001 |
| institution | Directory Open Access Journal |
| issn | 2699-9412 |
| language | English |
| last_indexed | 2024-12-20T15:24:33Z |
| publishDate | 2022-01-01 |
| publisher | Wiley-VCH |
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| series | Advanced Energy & Sustainability Research |
| spelling | doaj.art-b154e60160454b028cd3e766062bf0012022-12-21T19:35:54ZengWiley-VCHAdvanced Energy & Sustainability Research2699-94122022-01-0131n/an/a10.1002/aesr.202100138Fine‐Tuning the Photovoltaic Performance of Organic Solar Cells by Collaborative Optimization of Structural Isomerism and Halogen AtomZhe Li0Na Zhang1Honggang Chen2Hongjian Peng3Yingping Zou4College of Chemistry and Chemical Engineering Central South University Changsha Hunan 410083 ChinaCollege of Chemistry and Chemical Engineering Central South University Changsha Hunan 410083 ChinaCollege of Chemistry and Chemical Engineering Central South University Changsha Hunan 410083 ChinaCollege of Chemistry and Chemical Engineering Central South University Changsha Hunan 410083 ChinaCollege of Chemistry and Chemical Engineering Central South University Changsha Hunan 410083 ChinaFused‐ring acceptors based on an electron‐deficient core, such as Y6, have become a successful strategy in bulk heterojunction (BHJ) organic solar cells (OSCs) for high power conversion efficiencies (PCEs). Here, five fused‐ring electron acceptors (Y9, Y9‐2F, Y9‐2Cl, i‐Y9‐2F, i‐Y9‐2Cl) are synthesized using fused dithienothiophen[3,2‐b]pyrrolobenzotriazole and halogenated 1,1‐dicyanomethylene‐3‐indanone (IC) to investigate the effect of end‐group (EG) halogenation and structural isomerism on BHJ photovoltaic performance. Due to the strong electronegativity of halogens, all the acceptors with halogenated terminal units possess redshifted absorption spectra and deeper frontier energy levels compared with Y9. Different from asymmetric molecules i‐Y9‐2F and i‐Y9‐2Cl, Y9‐2F and Y9‐2Cl exhibit slightly lower bandgaps. Moreover, the devices based on fluorinated acceptors show more efficient charge collection, obtaining relatively high short‐circuit current density (J sc) and fill factor (FF). The lowest unoccupied molecular orbital energy levels of halogenated acceptors are similar. As a result, OSCs based on poly[(2,6‐(4,8‐bis(5‐(2‐ethylhexyl)thiophen‐2‐yl)‐benzo[1,2‐b:4,5‐b′]dithio‐phene))‐alt‐(5,5‐ (1′,3′‐di‐2‐thienyl‐5′,7′‐bis(2‐ethyl‐hexyl) benzo[1′,2′‐c:4′,5′‐c′]dithiophene‐4,8‐dione))] (PBDB‐T):Y9‐2F obtain more balanced J sc and open‐circuit voltage (V oc), and thus an optimal PCE of 15.49% is demonstrated with a V oc of 0.84 V, J sc of 26.30 mA cm−2, and FF of 70.05%.https://doi.org/10.1002/aesr.202100138end groupsfused-ring electron acceptorshalogenationstructural isomerism |
| spellingShingle | Zhe Li Na Zhang Honggang Chen Hongjian Peng Yingping Zou Fine‐Tuning the Photovoltaic Performance of Organic Solar Cells by Collaborative Optimization of Structural Isomerism and Halogen Atom Advanced Energy & Sustainability Research end groups fused-ring electron acceptors halogenation structural isomerism |
| title | Fine‐Tuning the Photovoltaic Performance of Organic Solar Cells by Collaborative Optimization of Structural Isomerism and Halogen Atom |
| title_full | Fine‐Tuning the Photovoltaic Performance of Organic Solar Cells by Collaborative Optimization of Structural Isomerism and Halogen Atom |
| title_fullStr | Fine‐Tuning the Photovoltaic Performance of Organic Solar Cells by Collaborative Optimization of Structural Isomerism and Halogen Atom |
| title_full_unstemmed | Fine‐Tuning the Photovoltaic Performance of Organic Solar Cells by Collaborative Optimization of Structural Isomerism and Halogen Atom |
| title_short | Fine‐Tuning the Photovoltaic Performance of Organic Solar Cells by Collaborative Optimization of Structural Isomerism and Halogen Atom |
| title_sort | fine tuning the photovoltaic performance of organic solar cells by collaborative optimization of structural isomerism and halogen atom |
| topic | end groups fused-ring electron acceptors halogenation structural isomerism |
| url | https://doi.org/10.1002/aesr.202100138 |
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