1452871-20-3Relevant academic research and scientific papers
The role of conjugated side chains in high performance photovoltaic polymers
Wang, Meng,Ma, Di,Shi, Keli,Shi, Shaowei,Chen, Song,Huang, Changjiang,Qiao, Zi,Zhang, Zhi-Guo,Li, Yongfang,Li, Xiaoyu,Wang, Haiqiao
, p. 2802 - 2814 (2015)
Four new D-A type copolymers, namely, PBDT-DFQX-PP, PBDT-DFQX-TP, PBDT-DFQX-PT and PBDT-DFQX-TT, were designed and synthesized to investigate the influence of conjugated side chain pattern on photovoltaic properties of conjugated polymers. All the four copolymers have an identical conjugated backbone comprising benzo[1,2-b:4,5-b′]dithiophene (BDT) donor unit and quinoxaline (Qx) acceptor unit, but with varying conjugated side chains, p-alkoxyphenyl or 2-alkylthienyl, attached to the donor and acceptor units, respectively. As evidenced by UV/Vis absorption spectra, electrochemical cyclic voltammetry, density functional theory (DFT), grazing incidence X-ray scattering (GIXS), transmission electron microscope (TEM) and photovoltaic measurements, the difference in conjugated side chain modulation led to totally different physicochemical properties. Among the four copolymers, PBDT-DFQX-TT exhibits the broadest absorption spectrum, the most close-packed structure as well as a finest fibril structure when blended with PC71BM. After systematic device optimization, the power conversion efficiencies (PCEs) of the bulk heterojunction (BHJ) photovoltaic devices based on the blends of PBDT-DFQX-PP, PBDT-DFQX-TP, PBDT-DFQX-PT and PBDT-DFQX-TT with PC71BM achieved 3.96%, 6.08%, 6.54% and 7.68%, respectively. By systematic varying the side chains of the copolymers from all phenyl groups to all thienyl ones, PCEs was increased by 250% from 3.96% to 7.68%. To date, PBDT-DFQX-TT is one of a few Qx-based PSCs that exhibits PCE exceeding 7.5%, and the results suggest that simultaneously modulating the conjugated side chains on both donor and acceptor units of copolymers could be an effective strategy for constructing high performance photovoltaic copolymers.
New benzo[1,2-b:4,5-b′]dithiophene-based small molecules containing alkoxyphenyl side chains for high efficiency solution-processed organic solar cells
Du, Zhengkun,Chen, Weichao,Wen, Shuguang,Qiao, Shanlin,Liu, Qian,Ouyang, Dan,Wang, Ning,Bao, Xichang,Yang, Renqiang
, p. 3319 - 3327 (2015/03/03)
A new acceptor-donor-acceptor (A-D-A) small molecule, namely, BDT-PO-DPP, based on the alkoxyphenyl (PO)-substituted benzo[1,2-b:4,5-b′]dithiophene (BDT) derivative and the diketopyrrolopyrrole (DPP) unit was synthesized as an electron donor for solution-processed small-molecule organic solar cells (SMOSCs). BDT-PO-DPP exhibited good thermal stability, with a 5% weight-lost temperature at 401°C under a nitrogen atmosphere. BDT-PO-DPP exhibited a lower HOMO energy level of -5.25 eV and a weaker aggregation ability than alkoxy-substituted BDT-O-DPP. A bulk heterojunction SMOSC device based on BDT-PO-DPP and [6,6]-phenyl-C61-butyric acid methyl ester was prepared, and it showed a power conversion efficiency up to 5.63% with a high open-circuit voltage of 0.83 V, a short circuit current density of 11.23 mA cm-2, and a fill factor of 60.37% by using 1,2-dichlorobenzene as the co-solvent after thermal annealing at 110°C. The results indicate that the alkoxyphenyl-substituted BDT derivative is a promising electron-donor building block for constructing highly efficient solution-processed SMOSCs.
New alkoxylphenyl substituted benzo[1,2-b:4,5-b′] dithiophene-based polymers: Synthesis and application in solar cells
Yuan, Jun,Xiao, Lu,Liu, Bo,Li, Yongfang,He, Yuehui,Pan, Chunyue,Zou, Yingping
, p. 10639 - 10645 (2013/09/23)
Two new alkoxylphenyl substituted benzo[1,2-b:4,5-b′]dithiophene (BDTPO)-based polymers (PBDTPO-DTBO and PBDTPO-DTBT) were synthesized. Their structures were verified by NMR spectroscopy, the molecular weights were determined by gel permeation chromatography (GPC), and the thermal properties were investigated by thermogravimetric analysis (TGA). UV-Vis absorption spectra of the polymers show broad and strong absorption bands from 300-750 nm both in CHCl3 solutions and films. The resulting copolymers exhibit relatively deep HOMO energy levels (-5.56 and -5.46 eV) and surprisingly high hole mobilities (2.2 × 10-1 and 3.3 × 10-2 cm2 V-1 s-1) for PBDTPO-DTBO and PBDTPO-DTBT, respectively. Preliminary photovoltaic properties of the copolymers blended with [6,6]-phenyl-C71 (or 61)-butyric acid methyl ester (PCBM) as an electron acceptor were investigated. The polymer solar cell (PSC) based on the single layer device structure of ITO/PEDOT:PSS/PBDTPO-DTBO:PC71BM (1:1.5, w/w)/Ca/Al demonstrates a high power conversion efficiency of 6.2% under the illumination of AM 1.5G, 100 mW cm-2.
New alkoxylphenyl substituted benzo[1,2-b:4,5-b′] dithiophene-based polymers: Synthesis and application in solar cells
Yuan, Jun,Xiao, Lu,Liu, Bo,Li, Yongfang,He, Yuehui,Pan, Chunyue,Zou, Yingping
, p. 10639 - 10645 (2013/09/12)
Two new alkoxylphenyl substituted benzo[1,2-b:4,5-b′]dithiophene (BDTPO)-based polymers (PBDTPO-DTBO and PBDTPO-DTBT) were synthesized. Their structures were verified by NMR spectroscopy, the molecular weights were determined by gel permeation chromatography (GPC), and the thermal properties were investigated by thermogravimetric analysis (TGA). UV-Vis absorption spectra of the polymers show broad and strong absorption bands from 300-750 nm both in CHCl3 solutions and films. The resulting copolymers exhibit relatively deep HOMO energy levels (-5.56 and -5.46 eV) and surprisingly high hole mobilities (2.2 × 10-1 and 3.3 × 10-2 cm2 V-1 s-1) for PBDTPO-DTBO and PBDTPO-DTBT, respectively. Preliminary photovoltaic properties of the copolymers blended with [6,6]-phenyl-C71 (or 61)-butyric acid methyl ester (PCBM) as an electron acceptor were investigated. The polymer solar cell (PSC) based on the single layer device structure of ITO/PEDOT:PSS/PBDTPO-DTBO:PC71BM (1:1.5, w/w)/Ca/Al demonstrates a high power conversion efficiency of 6.2% under the illumination of AM 1.5G, 100 mW cm-2.
