1304773-88-3Relevant academic research and scientific papers
5-alkyloxy-6-fluorobenzo[c][1,2,5]thiadiazole- and silafluorene-based D-A alternating conjugated polymers: Synthesis and application in polymer photovoltaic cells
Li, Guangwu,Kang, Chong,Gong, Xue,Zhang, Jicheng,Li, Cuihong,Chen, Youchun,Dong, Huanli,Hu, Wenping,Li, Fenghong,Bo, Zhishan
, p. 4645 - 4652 (2014/08/05)
Three donor-acceptor (D-A) alternating conjugated polymers with silafluorene as the donor unit, 5-alkyloxy-6-fluorobenzothiadiazole as the acceptor unit, and thiophene as the spacer has been synthesized and used as donor materials for polymer solar cells (PSCs). The introduction of a fluorine atom on the benzothiadiazole unit can lower the HOMO and LUMO energy level of the resulted polymers to afford higher open circuit voltage (Voc); whereas the introduction of a flexible alkyloxy chain on benzothiadiazole unit can increase the solubility of the resulted polymers without interfering the close packing of polymer chains in the solid state. High molecular weight polymers P-1a, P-1b, and P-1c, which are fully soluble in 1,2-dichorobenzene (DCB) at elevated temperature, have been prepared by Suzuki polycondensation. Among these polymers, P-1c exhibited the highest hole mobility up to 1.36 × 10-2 cm2 V-1 s-1. PSCs based P-1b:PC71BM demonstrated the highest Voc up to 0.98 V. P-1a:PC71BM based PSCs gave the highest power conversion efficiency (PCE) of 6.41%, which is the highest value among solar cells with benzothiadiazole- and silafluorene-containing polymers as the donor material.
5,6-Difluorobenzothiadiazole and silafluorene based conjugated polymers for organic photovoltaic cells
Li, Guangwu,Kang, Chong,Gong, Xue,Zhang, Jicheng,Li, Weiwei,Li, Cuihong,Dong, Huanli,Hu, Wenping,Bo, Zhishan
, p. 5116 - 5123 (2014/07/07)
To achieve 5,6-difluorobenzothiadiazole and 2,7-linked silafluorene based soluble conjugated polymers, flexible side chains were attached at different positions of the conjugated polymers. Three soluble polymers PSiF-D(OT)DFBT, PSiF-TTDFBT, and PDOSiF-DTDFBT were prepared and used as donor materials for polymer solar cells. PSiF-D(OT)DFBT exhibits a band gap of 2.06 eV with a deep HOMO of -5.64 eV. PSiF-TTDFBT shows a band gap of 1.75 eV with the HOMO of -5.23 eV. PDOSiF-DTDFBT is of a band gap of 1.86 eV with the HOMO level of -5.37 eV. Among these three polymers, PDOSiF-DTDFBT shows the highest field effect transistor (FET) hole mobility up to 3.31 × 10-2 cm2 V-1 s-1, PDOSiF-DTDFBT:PC71BM blend films show the highest SCLC mobility up to 5.10 × 10-4 cm2 V-1 s-1, and polymer solar cells (PSCs) with the blend of PDOSiF-DTDFBT:PC71BM (1:1, by weight) as the active layer gave a power conversion efficiency (PCE) of 4.03% with an open circuit voltage (V oc) of 0.73 V, a short circuit current (Jsc) of 8.55 mA cm-2, and a fill factor (FF) of 0.65. Our studies also reveal the structure-property relationship of 2,7-linked silafluorene and 5,6-difluorobenzothiadiazole based conjugated polymers.
Structural variation of donor-acceptor copolymers containing benzodithiophene with bithienyl substituents to achieve high open circuit voltage in bulk heterojunction solar cells
Kularatne, Ruvini S.,Taenzler, Ferdinand J.,Magurudeniya, Harsha D.,Du, Jia,Murphy, John W.,Sheina, Elena E.,Gnade, Bruce E.,Biewer, Michael C.,Stefan, Mihaela C.
, p. 15535 - 15543 (2013/12/04)
Three new donor-acceptor copolymers P1, P2, and P3 were synthesized with benzodithiophene with bithienyl substituents as the donor and 5,6-difluorobenzo[c][1,2,5]thiadiazole, 4,7-di(thiophen-2-yl)benzo[c][1,2,5] thiadiazole, and 5,6-difluoro-4,7-di(thiophen-2-yl)benzo[c][1,2,5]thiadiazole as the acceptors, respectively. The insertion of thiophene spacer between the donor and the acceptor broadened the absorption of the polymers P2 and P3 and resulted in a red shift of ~30 nm as compared to that of the polymer P1. However, the inclusion of fluorine atoms on the polymer had detrimental effects on the photovoltaic properties of the polymers. The synthesized donor-acceptor polymers were tested in bulk heterojunction (BHJ) solar cells with [6,6]-phenyl C71 butyric acid methyl ester (PC71BM) acceptor. Polymer P2 gave a PCE of 3.52% with PC71BM in which the active layer was prepared in chloroform with 3% v/v 1,8-diiodooctane (DIO) additive. The effect of fluorine substitution and thiophene group insertion on the UV/Vis absorbance, photovoltaic performances, morphology, and charge carrier mobilities for the polymers are discussed.
