1215857-68-3Relevant articles and documents
Solution-processed and high-performance organic solar cells using small molecules with a benzodithiophene unit
Zhou, Jiaoyan,Zuo, Yi,Wan, Xiangjian,Long, Guankui,Zhang, Qian,Ni, Wang,Liu, Yongsheng,Li, Zhi,He, Guangrui,Li, Chenxi,Kan, Bin,Li, Miaomiao,Chen, Yongsheng
, p. 8484 - 8487 (2013)
Three small molecules named DR3TBDTT, DR3TBDTT-HD, and DR3TBD2T with a benzo[1,2-b:4,5-b′]dithiophene (BDT) unit as the central building block have been designed and synthesized for solution-processed bulk-heterojunction solar cells. Power conversion efficiencies (PCEs) of 8.12% (certified 7.61%) and 8.02% under AM 1.5G irradiation (100 mW cm-2) have been achieved for DR3TBDTT- and DR3TBDT2T-based organic photovoltaic devices (OPVs) with PC 71BM as the acceptor, respectively. The better PCEs were achieved by improving the short-circuit current density without sacrificing the high open-circuit voltage and fill factor through the strategy of incorporating the advantages of both conventional small molecules and polymers for OPVs.
Photoactive Organic/Inorganic Hybrid Materials with Nanosegregated Donor–Acceptor Arrays
Zhu, Xiaolei,Hessin, Cheriehan,Salamé, Aude,Sosa-Vargas, Lydia,Kreher, David,Adachi, Chihaya,Proust, Anna,Mialane, Pierre,Marrot, Jérome,Bouchet, Aude,Sliwa, Michel,Méry, Stéphane,Heinrich, Beno?t,Mathevet, Fabrice,Izzet, Guillaume
, p. 8419 - 8424 (2021)
The synthesis of the first mesogenic donor-acceptor polyoxometalate (POM)-based hybrid is herein described. The structural and electronic properties of the hybrid compound were evaluated through combination of small- and wide-angle X-ray scattering, optical microscopy, electrochemistry and photoluminescence. In the solid state, the compound behaves as a birefringent solid, displaying a lamellar organization in which double-layers of POMs and bis(thiophene)thienothiophene organic donors alternate regularly. Noticeably, the sub-unit organizations in the composite are similar to that observed for the individual POM and organic donor precursors. Photophysical studies show that in the hybrid, the fluorescence of the organic donor unit is considerably quenched both in solution and in the solid state, which is attributed to occurrence of intramolecular charge-separated state.
Synthesis and characterization of highly conjugated side-group-substituted benzo[1,2-b:4,5-b′]dithiophene-based copolymer for use in organic solar cells
Kim, Jiyoung,Park, Jong Baek,Lee, Woo-Hyung,Moon, Jiwon,Kim, Joonghan,Hwang, Do-Hoon,Kang, In-Nam
, p. 653 - 660 (2018)
A new donor–acceptor (D–A) conjugated copolymer based on benzo[1,2-b:4,5-b′]dithiophene (BDT) and thieno[3,4-c]pyrrole-4,6-dione (TPD) was synthesized via a Stille cross-coupling reaction. A highly conjugated thiophene-based side group, tris(thienylenevinylene) (TTV), was incorporated into each BDT unit to generate the two-dimensional D–A copolymer (PBDT-TTV). An alkoxy-substituted BDT-based TPD copolymer (PBDT-OR) was synthesized using the same polymerization method for comparison. PBDT-TTV thin films produced two distinct absorption peaks. The shorter wavelength absorption (458 nm) was attributed to the BDT units containing the TTV group, and the longer wavelength band (567–616 nm) was attributed to intramolecular charge transfer between the BDT donor and the TPD acceptor. The highest occupied molecular orbital energy levels of PBDT-OR and PBDT-TTV were calculated to be ?5.53 and ?5.61 eV, respectively. PBDT-TTV thin films harvested a broad solar spectrum covering the range 300–700 nm. A comparison with the PBDT-OR films revealed stronger interchain π–π interactions in the PBDT-TTV films and, thus, a higher hole mobility. A polymer solar cell device prepared using PBDT-TTV as the active layer was found to exhibit a higher power conversion efficiency than a device prepared using PBDT-OR under AM 1.5 G (100 mW/cm2) conditions.
Quinoxaline-based D-A conjugated polymers for organic solar cells: Probing the effect of quinoxaline side chains and fluorine substitution on the power conversion efficiency
Choi, Suna,Park, Gi Eun,Lee, Dae Hee,Godumala, Mallesham,Cho, Min Ju,Choi, Dong Hoon
, p. 1209 - 1218 (2017)
We describe the successful synthesis of four novel donor-acceptor (D-A) type copolymers, referred to as PQxBT, PQxFBT, TQxBT, and TQxFBT. The effects of using a fluorinated bithiophene (FBT) and varying the side-chain moieties tethered to the quinoxaline (Qx) unit (electron-withdrawing group in the polymer backbone) on the physical properties and photovoltaic performance were investigated. Specifically, the four polymers were synthesized using either alkoxyphenyl (P) or alkylthiophene (T) units anchored to the quinoxaline in the polymer backbone. The FBT-bearing polymers, PQxFBT and TQxFBT, displayed more redshifted absorption spectra and higher crystallinity owing to the greater planarity of their polymer backbone as compared to the non-fluorinated polymers. The TQxFBT copolymer, equipped with both the alkylthiophene side chains and FBT, exhibited face-on orientation in film state and a well-mixed nanophase morphology in TQxFBT:PC71BM blend films. The photovoltaic device fabricated from TQxFBT:PC71BM exhibited the highest power conversion efficiency of 4.18%.
Dithienobenzimidazole-containing conjugated donor–acceptor polymers: Synthesis and characterization
Harris, Jared D.,Stihl, Markus,Schmidt, Hans-Werner,Carter, Kenneth R.
, p. 60 - 69 (2019)
The synthesis of two new conjugated polymers based on the relatively under-exploited monomer, 5,8-dibromo-2-[5-(2-hexyldecyl)-2-thienyl]-1H-dithieno[3,2-e:2′,3′-g]benzimidazole (dithienobenzimidazole, DTBI), and either 4,7-bis[4-hexyl-5-(trimethylstannyl)-2-thienyl]-2,1,3-benzothiadiazole (BTD) or 2,6-bis(trimethylstannyl)-4,8-bis(5-(2-ethylhexyl) thiophen-2-yl)benzo[1,2-b:4,5-b′]dithiophene (BDT) is described. The polymers were synthesized via Stille polycondensation and characterized by traditional methods (1H NMR, gel-permeation chromatography, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, thermal gravimetric analysis, differential scanning calorimetry, ultraviolet–visible spectroscopy, photoluminescence, and cyclic voltammetry). Prior to their synthesis, trimer structures were modeled by DFT calculations facilitating a further understanding of the systems' electronic and geometric structure. Polymers were titrated with acid and base to take advantage of their amphiprotic imidazole moiety and their optical response monitored with ultraviolet–visible spectroscopy. Finally, pristine polymer thin-films were treated with acid and base to evaluate (de)protonation's effect on system electronics, but thin-film degradation was encountered.
Solution-processable oligothiophene derivatives with branched alkyl chains and their thin-film transistor characteristics
Lu, Ming,Nagamatsu, Shuichi,Yoshida, Yuji,Chikamatsu, Masayuki,Azumi, Reiko,Yase, Kiyoshi
, p. 60 - 61 (2010)
Introduction of branched alkyl chains at the terminal positions of sexithiophene drastically improves the solubility of the compound, while still maintaining satisfactory charge carrier mobility. Field-effect transistors based on spin-coated films of the sexithiophene derivative exhibited p-type characteristics. Post thermal treatment enhanced crystallinity of the films and afforded a field-effect mobility of 0.11-0.18 cm2 V-1 s-1 and an on/off ratio of 104.
The steric effect of benzodifuran based polymers: Via alkyl side chain manipulation: A simple approach for enhancing the photovoltaic performance
Fu, Hai-Yan,Gao, Pan-Feng,Wang, Li-Yong,Zhang, Jian-Yi
, p. 549 - 558 (2022/01/22)
A series of narrow band gap conjugated copolymers with different alkyl side chains were synthesized via Stille copolymerization of benzodifuran (BDF) and benzothiadiazole (BT) monomers. The origination effect of the alkyl side chains, linked to the thienyl side groups of BDF based backbone, on the optical, electronic and morphological properties of the resulting polymers were investigated and correlated with the photovoltaic performance. It was found that the different alkyl side chains positions have a significant impact on the polymeric optoelectronic properties due to differences of torsion in the backbones. The best performance of the bulk-heterojunction solar cells (BHJ) with a power conversion efficiency (PCE) of 6.73% was achieved with PBFDBT-o as the donor and (6,6)-phenyl-C71-butyric acid methyl ester (PC71BM) as the acceptor, which can be attributed to its higher charge carrier mobility as well as the optimized interpenetrating network with respect to the other two polymers. The results demonstrated that the alkyl side chain position manipulations play a crucial role in adjusting the optoelectronic properties of BDF based copolymers and it is a promising molecular design strategy for the application of solar cells.
Compound based on benzo [1, 2-b: 4, 5-b '] dithiophene and preparation method thereof
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Paragraph 0076; 0080-0082, (2020/09/12)
The present invention provides a compound based on benzo [1, 2-b: 4, 5-b '] dithiophene, the compound has a structure represented by a formula (I), R1 is-CH, R2 is-CH, and n is aneven number selected from 1-20. The invention also provides a preparation method of the compound based on benzo [1, 2-b: 4, 5-b '] dithiophene. In a compound system provided by the invention, pi electrons have a larger delocalization range, so that pi-pi stacking between molecules can be better realized, charge transmission is facilitated, and the open-circuit voltage and the photoelectric conversion efficiency oforganic small-molecule solar cells based on the compound can be effectively improved. And the preparation method is simple, efficient and high in yield.
Side chain effect on poly(beznodithiophene-co-dithienobenzoquinoxaline) and their applications for polymer solar cells
Fan, Jingzhe,Zhang, Yong,Lang, Caili,Qiu, Meng,Song, Jinsheng,Yang, Renqiang,Guo, Fengyun,Yu, Qingjiang,Wang, Jinzhong,Zhao, Liancheng
, p. 228 - 237 (2015/12/18)
Two conjugated polymers (PBDT86-TQ and PBDT88-TQ) with different side chains, but with the same polymer backbone, have been prepared for polymer solar cells. The side chains in the two polymers induced different steric hindrance. PBDT86-TQ showed the 0-0 absorption peak at ~740 nm, and it was blue-shifted to ~660 nm for PBDT88-TQ as a result of strong steric hindrance from two dioctyl chains. Further, the HOMO energy levels of PBDT86-TQ (-5.10 eV) and PBDT88-TQ (-5.54 eV) also showed a large difference. The hole mobility of PBDT88-TQ is ~70 times higher than that of PBDT86-TQ. The photovoltaic cells based on PBDT86-TQ gave a very low PCE of 0.69-0.80%, and for PBDT88-TQ-based cells, the PCEs were improved to 3.70-4.50% with a Voc of up to 0.98 V and improved Jsc and FF. These results show the importance of side chains on the design of conjugated polymers for high performance polymer solar cells.
Synthesis and photovoltaic properties of two-dimensional benzodithiophene-thiophene copolymers with pendent rational naphtho[1,2-c:5,6-c]bis[1,2,5]thiadiazole side chains
Xu, Xiaopeng,Feng, Kui,Li, Kai,Peng, Qiang
, p. 23149 - 23161 (2015/11/28)
A series of new two-dimensional copolymers, PBDTT-TABT, PBDTT-TANT and PBDTT-TSNT, with conjugated benzodiathiazole (BT) or naphthobisthiadiazole (NT) side chains were successfully synthesized and characterized for high performance polymer solar cells (PSCs). The NT unit showed a stronger electron-withdrawing ability and a larger conjugation than the BT unit, which induced a stronger ICT process between the benzodithiophene (BDT)-thiophene (T) backbone and the conjugated side chain for NT containing copolymers. As a result, PBDTT-TANT and PBDTT-TSNT showed lower-lying bandgaps and more red-shifted absorption than PBDTT-TABT. The alkylthio modification effect of conjugated side chains was also investigated in this work. This effect showed a positive role in lowering the HOMO energy level, and a negative role in elevating carrier mobility and molecular stacking properties in our two-dimensional polymeric systems. Bulk heterojunction (BHJ) PSCs were fabricated using these copolymers as the donor materials to evaluate their photovoltaic properties. The PBDTT-TABT, PBDTT-TANT and PBDTT-TSNT devices exhibited PCEs of 4.60%, 5.65% and 4.01%, respectively. In spite of the Voc values, the highest Jsc, FF and PCE were achieved for the PBDTT-TANT device, which was attributed to its red-shifted absorption, improved carrier mobility and well-defined phase separation. It is interesting that the Jscs, FFs and PCEs of all these devices were elevated significantly when made using the solvent vapor annealing (SVA) method. The THF-SVA process would provide a driving force to facilitate the formation of a much more well-defined surface morphology, resulting in the enhanced Jsc and FF values. The PBDTT-TANT device showed the highest PCE of 8.04%, which is the top efficiency for this type of two-dimensional copolymer with donor (D)-donor (D) polymer backbones and donor (D)-acceptor (A) conjugated side chains. Our design strategy would give an instructive guide to developing high performance two-dimensional polymer donors to be used in organic photovoltaic applications.