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.
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.
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.
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.
