- Alternating copolymers of carbazole and triphenylamine with conjugated side chain attaching acceptor groups: Synthesis and photovoltaic application
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Four alternating copolymers of carbazole (Cz) and triphenylamine (TPA) with thienylenevinylene (TV) conjugated side chain containing different acceptor end groups of aldehyde (PCzTPATVCHO), monocyano (PCzTPA-TVCN) dicyano (PCzTPA-TVDCN), and 1,3-diethyl-2-thiobarbituric acid (PCzTPA-TVDT), have been designed and synthesized. The structures and properties of the main chain donor-side chain acceptor D-A copolymers were fully characterized. Through changing the acceptor group attached to the TV conjugated side chain on TPA, the electronic properties and energy levels of the copolymers were effectively tuned. The effect of substituent on the electronic structures of the copolymers was also studied by molecular simulation. These results indicate that it is a simple and effective approach to tune the bandgap in a conjugated polymer by attaching an acceptor end group on the conjugated side chains. PCzTPA-TVCN, PCzTPA-TVDCN, and PCzTPA-TVDT were used as donor in polymer solar cells; the device based on PCzTPA-TVDT/PC70BMdemonstrates a power conversion efficiency of 2.76% withVoc of 0.87 V under the illumination of AM1.5G, 100 mW/cm2.
- Zhang, Zhi-Guo,Liu, Yi-Liang,Yang, Yang,Hou, Keyue,Peng, Bo,Zhao, Guangjin,Zhang, Maojie,Guo, Xia,Kang, En-Tang,Li, Yongfang
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- A selenophene analogue of PCDTBT: Selective fine-tuning of LUMO to lower of the bandgap for efficient polymer solar cells
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In an attempt to further improve the performance of the PCDTBT-based polymer solar cells (PSCs), we have synthesized a selenophene analogue of PCDTBT, namely, PCDSeBT, in which diselenienylbenzothiadiazole (DSeBT) monomer alternately flanks with a 2,7-carbazole unit. The intrinsic properties of PCDSeBT are not only characterized by UV-vis absorption, cyclic voltammetry (CV), and organic field-effect transistors (OFETs) but also the surface morphology, mobilities of space charge-limited current (SCLC) model, and polymer solar cells (PSCs) in its bulk-heterojunction (BHJ) active layer with [6,6]-phenyl C71-butyric acid methyl ester (PC71BM) are evaluated in detail. It is found that PCDSeBT simultaneously has a low-lying highest occupied molecular orbital (HOMO) energy level at -5.4 eV and a low bandgap of 1.70 eV as required by the ideal polymers for BHJ PSCs. The high current of 11.7 mA/cm2 is obtained for PCDSeBT-based PSCs, to our knowledge, which is among the highest short-circuit current density (J SC) values obtained from a BHJ device consisting of PCDTBT derivatives and [6,6]-phenyl C61-butyric acid methyl ester (PCBM). The high JSC value, along with a moderate fill factor (FF) of 45% and a high open-circuit voltage (VOC) of 0.79 V, yields a power conversion efficiency (PCE) of 4.12%, which is about 37% increase in PCE from a PCDTBT-based reference device. On the basis of our results, one can be concluded that the DSeBT placement for construction of donor (D)-acceptor (A) polymers is an easy and effective way to realize both the higher JSC and V OC values in PSCs, as a consequence of the selective lower-lying lowest unoccupied molecular orbital (LUMO) with the HOMO being almost unchanged, together with the effective broadening on the absorption band.
- Kim, Boram,Yeom, Hye Rim,Yun, Myoung Hee,Kim, Jin Young,Yang, Changduk
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- Bridging Small Molecules to Conjugated Polymers: Efficient Thermally Activated Delayed Fluorescence with a Methyl-Substituted Phenylene Linker
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Based on a “TADF + Linker” strategy (TADF=thermally activated delayed fluorescence), demonstrated here is the successful construction of conjugated polymers that allow highly efficient delayed fluorescence. Small molecular TADF blocks are linked together
- Rao, Jiancheng,Liu, Xinrui,Li, Xuefei,Yang, Liuqing,Zhao, Lei,Wang, Shumeng,Ding, Junqiao,Wang, Lixiang
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p. 1320 - 1326
(2019/12/24)
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- A General and Air-tolerant Strategy to Conjugated Polymers within Seconds under Palladium(I) Dimer Catalysis
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While current M0/MII based polymerization strategies largely focus on fine-tuning the catalyst, reagents and conditions for each and every monomer, this report discloses a single method that allows access to a variety of different conjugated polymers within seconds at room temperature. Key to this privileged reactivity is an air- and moisture stable dinuclear PdI catalyst. The method is operationally simple, robust and tolerant to air.
- Magnin, Guillaume,Clifton, Jamie,Schoenebeck, Franziska
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p. 10179 - 10183
(2019/06/25)
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- Carbazole-based π-conjugated polyazomethines: Effects of catenation and comonomer insertion on optoelectronic features
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A series of carbazole-based polyazomethines have been synthesized under micro-wave irradiation and without transition-metal based catalyst. The impact of both the catenation brought by the carbazole subunits and the insertion of a co-monomer, i.e. 3,4 ethylene dioxythiophene (EDOT), on the optical and electrochemical properties have been studied. Among the different polyazomethines synthesized, the best in terms of optical and electrochemical properties has been found to be the one with the azomethine function linked in positions 2,7 of carbazole subunits. Upon the insertion of the EDOT comonomer, an increase of the molecular weight and a red-shift in the absorption spectra has been observed, corresponding to a diminution of the electronic gap.
- Garbay,Muccioli,Pavlopoulou,Hanifa,Hadziioannou,Brochon,Cloutet
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p. 274 - 284
(2017/05/31)
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- organic semiconductor compound, manufacturing method thereof, and organic electronic device that contains it
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The present invention relates to an organic semiconductor compound, a method for manufacturing the same, and an organic electronic device comprising the same and, more specifically, to an organic semiconductor compound including quinoxaline, a method for manufacturing the same, and an organic electronic device comprising the same. In addition, by having a low band gap by synthesizing and copolymerizing a thiophene derivative containing sulfur (S) with a quinoxaline-based compound, the organic electronic device comprising the same has a higher efficiency with an innovative combination with a fullerene derivative, which is a photoactive layer, with the organic semiconductor compound of the present invention. The organic semiconductor compound of the present invention has high thermal stability and high solubility and the organic electronic device comprising the same has excellent electric characteristics, thereby can be valuably used as a n-type material of the organic electronic device, especially an organic solar cell or an organic thin film transistor.
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- Synthesis and structure-property relationship of carbazole-alt-benzothiadiazole copolymers
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A series of four π-conjugated carbazole-alt-benzothiadiazole copolymers (PCBT) were prepared by Suzuki cross-coupling reaction between synthesized dibromocarbazoles as electron-rich subunits and 4,7-bis(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-2,1,3-benzothiadiazole as electron-deficient subunits. The subunits were directly linked through 2,7- or 3,6- positions of the carbazole. In addition, the carbazole monomers have been N-substituted by a branched or a linear side-chain. The chemical structure of the copolymers and their precursors was confirmed by NMR and IR spectroscopies, and their molar masses were estimated by SEC. Thermal analysis under N2 atmosphere showed no weight loss below 329°C, and no glass transition was observed in between 0 and 250°C. The band gaps of all PCBTs evaluated by optical spectroscopies and by cyclic voltammetry analysis were consistent with expectations and ranged between 2.2 and 2.3 eV. Finally, 2,7 and 3,6 linkages were shown to influence optical properties of PCBTs.
- Oriou, Jules,Ng, Feifei,Hadziioannou, Georges,Brochon, Cyril,Cloutet, Eric
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p. 2059 - 2068
(2015/08/03)
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- A versatile approach to organic photovoltaics evaluation using white light pulse and microwave conductivity
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State-of-the-art low band gap conjugated polymers have been investigated for application in organic photovoltaic cells (OPVs) to achieve efficient conversion of the wide spectrum of sunlight into electricity. A remarkable improvement in power conversion efficiency (PCE) has been achieved through the use of innovative materials and device structures. However, a reliable technique for the rapid screening of the materials and processes is a prerequisite toward faster development in this area. Here we report the realization of such a versatile evaluation technique for bulk heterojunction OPVs by the combination of time-resolved microwave conductivity (TRMC) and submicrosecond white light pulse from a Xe-flash lamp. Xe-flash TRMC allows examination of the OPV active layer without requiring fabrication of the actual device. The transient photoconductivity maxima, involving information on generation efficiency, mobility, and lifetime of charge carriers in four well-known low band gap polymers blended with phenyl-C61-butyric acid methyl ester (PCBM), were confirmed to universally correlate with the PCE divided by the open circuit voltage (PCE/Voc), offering a facile way to predict photovoltaic performance without device fabrication.
- Saeki, Akinori,Yoshikawa, Saya,Tsuji, Masashi,Koizumi, Yoshiko,Ide, Marina,Vijayakumar, Chakkooth,Seki, Shu
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p. 19035 - 19042
(2013/01/15)
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