- Regulating exciton bonding energy and bulk heterojunction morphology in organic solar cells: Via methyl-functionalized non-fullerene acceptors
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Electron-deficient end groups (EGs) are very important for non-fullerene small molecule acceptors (NF-SMAs) to tune their absorption, energy levels, and crystallization properties. Herein, we designed and synthesized three SMAs, namely, BTTIC-0M, BTTIC-2M, and BTTIC-4M by adding the methyl unit into 2-(6-oxo-5,6-dihydro-4H-cyclopenta[c]thiophen-4-ylidene)malononitrile (CPTCN). Methyl group, with its slight electron-donating ability, significantly elevates the LUMO energy levels but does not seriously affect the bandgaps of the CPTCN-based SMAs, which helps to reduce the energy loss (Eloss). In-depth dynamic theoretical simulations of the donor-acceptor (D-A) complex reveal that the exciton bonding energy (BE) can be fine-tuned by continuously increasing the methyl groups on the end groups of the SMAs. Methyl-substituted EG reduces the driving force and also enhances the BE of the charge transport (CT) state exciton, leading to a decrease in the exciton dissociation efficiencies. However, we found that one methyl-functionalized CPTCN enables PBDB-T:BTTIC-2M-based organic solar cells (OSCs) to achieve a power conversion efficiency (PCE) as high as 13.15%. Though PBDB-T:BTTIC-2M-based OSCs exhibit a slightly lower exciton dissociation efficiency than those of PBDB-T:BTTIC-0M, a more favorable superficial and internal morphology is attained in the PBDB-T:BTTIC-2M bulk-heterojunction layer, which balances the electron and hole mobilities and diminishes the bimolecular recombination. Comparatively, BTTIC-4M failed to realize a high performance owing to its adverse interactions with the polymer chain and the multiscale phase separation in the blend films. Actually, adjusting the number of methyl groups on the end group is done to compensate the current-voltage losses within the OSC devices with complicated contributions from absorption spectra, LUMO energy levels, exciton bonding energies, and morphologies.
- Gao, Wei,Liu, Tao,Luo, Zhenghui,Zhang, Lin,Ming, Ruijie,Zhong, Cheng,Ma, Wei,Yan, He,Yang, Chuluo
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supporting information
p. 6809 - 6817
(2019/03/26)
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- Thieno[3,2-b]thiophene-2-carboxylic acid derivatives as GPR35 agonists
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The optimization of a series of thieno[3,2-b]thiophene-2-carboxylic acid derivatives for agonist activity against the GPR35 is reported. Compounds were optimized to achieve β-arrestin-biased agonism for developing probe molecules that may be useful for elucidating the biology and physiology of GPR35. Compound 13 was identified to the most potent GPR35 agonist, and compounds 30 and 36 exhibited the highest efficacy to cause β-arrestin translocation.
- Deng, Huayun,Hu, Jieyu,Hu, Haibei,He, Mingqian,Fang, Ye
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scheme or table
p. 4148 - 4152
(2012/07/03)
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- Photochromic dihetarylethenes 6. Photochromic derivatives of thieno[3,2-b]thiophene
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1,2-Bis{5-(2-benzothiazolyl)-2-methyl-6-trifluoromethylthieno[3,2-b]thiophen-3-y l}hexafluorocyclopentene possessing high fatigue resistance was synthesized for the first time. Its photochromic and fluorescence properties were studied. The structure of it
- Krayushkin,Stoyanovich,Zolotarskaya,Murav'ev,Martynkin,Vorontsova,Starikova,Ivanov,Uzhinov
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p. 110 - 115
(2007/10/03)
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- Synthesis, polymerization and characterization of substituted dithieno [3,4-b: 3',4'-d] thiophenes
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Chemical or electrochemical oxidation of substituted dithieno [3,4- b:3',4'-d]thiophenes provides polymers with defined regiochemical structures. These materials have lower bandgaps (0.7-0.9 eV) than the unsubstituted fused heteroarene. Potential cycling of the 1,3-dimethyl substituted polymer film shows repetitive p- and n-dopability. The chemically-prepared dioctyl analog is soluble in common solvents such as chloroform, dichloromethane and THF. However, overoxidation of the polymers at an electrode surface presents a limitation to the polymerization of substituted analogs of the parent fused heteroarene.
- Inaoka, Seiji,Collard, David M.
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p. 1719 - 1725
(2007/10/03)
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- Halogenation Using Quaternary Ammonium Polyhalides. XXXI. Halogenation of Thiophene Derivatives with Benzyltrimethylammonium Polyhalides
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The reactions of thiophene derivatives with benzyltrimethylammonium tetrachloroiodate, benzyltrimethylammonium tribromide, and benzyltrimethylammonium dichloroiodate in acetic acid or in acetic acid-zinc chloride under mild conditions gave chloro-, bromo-, and iodo-substituted thiophene derivatives, respectively, in satifactory yields.
- Okamoto, Tsuyoshi,Kakinami, Takaaki,Fujimoto, Hiroshi,Kajigaeshi, Shoji
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p. 2566 - 2568
(2007/10/02)
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