- Dithienosilole extended BODIPYs: Synthesis and spectroscopic properties
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3,/3,5-Dithienosilole-vinyl-BODIPYs were readily synthesized through Knoevenagel condensation reactions. Spectroscopic properties of two dyes in various solvents were investigated. Dyes 1 and 2 show an absorption maxima at 620 and 738 nm with absorption coefficient of 60900 and 77900 M-1· cm-1 in DCM, respectively. Significant red shifts of the main spectral bands are observed relative to that of the parent 1,3,5,7-tetramethyl-BODIPY. TD-DFT calculations reproduce the spectral shifts and experimental spectra.
- Sun, Yijuan,Gai, Lizhi,Wang, Yitong,Qu, Zhirong,Lu, Hua
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- PROCESS FOR PRODUCING FUSED-RING AROMATIC COMPOUND, AND CONJUGATED POLYMER
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The invention addresses a problem of purifying a monomer to be a precursor according to a simpler and milder method so as to obtain a polymer having a higher molecular weight. The invention relates to a method for producing a condensed polycyclic aromatic compound having n active groups (wherein n is an integer of 1 or more and 4 or less), which comprises bringing a composition containing the condensed polycyclic aromatic compound and a solvent into contact with zeolite.
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Paragraph 0239; 0240; 0241; 0244; 0245
(2014/09/29)
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- Synthetic principles directing charge transport in low-band-gap dithienosilole-benzothiadiazole copolymers
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Given the fundamental differences in carrier generation and device operation in organic thin-film transistors (OTFTs) and organic photovoltaic (OPV) devices, the material design principles to apply may be expected to differ. In this respect, designing organic semiconductors that perform effectively in multiple device configurations remains a challenge. Following "donor-acceptor" principles, we designed and synthesized an analogous series of solution-processable π-conjugated polymers that combine the electron-rich dithienosilole (DTS) moiety, unsubstituted thiophene spacers, and the electron-deficient core 2,1,3-benzothiadiazole (BTD). Insights into backbone geometry and wave function delocalization as a function of molecular structure are provided by density functional theory (DFT) calculations at the B3LYP/6-31G(d,p) level. Using a combination of X-ray techniques (2D-WAXS and XRD) supported by solid-state NMR (SS-NMR) and atomic force microscopy (AFM), we demonstrate fundamental correlations between the polymer repeat-unit structure, molecular weight distribution, nature of the solubilizing side-chains appended to the backbones, and extent of structural order attainable in p-channel OTFTs. In particular, it is shown that the degree of microstructural order achievable in the self-assembled organic semiconductors increases largely with (i) increasing molecular weight and (ii) appropriate solubilizing-group substitution. The corresponding field-effect hole mobilities are enhanced by several orders of magnitude, reaching up to 0.1 cm2 V-1 s-1 with the highest molecular weight fraction of the branched alkyl-substituted polymer derivative in this series. This trend is reflected in conventional bulk-heterojunction OPV devices using PC71BM, whereby the active layers exhibit space-charge-limited (SCL) hole mobilities approaching 10-3 cm2 V-1 s-1, and yield improved power conversion efficiencies on the order of 4.6% under AM1.5G solar illumination. Beyond structure-performance correlations, we observe a large dependence of the ionization potentials of the polymers estimated by electrochemical methods on polymer packing, and expect that these empirical results may have important consequences on future material study and device applications.
- Beaujuge, Pierre M.,Tsao, Hoi Nok,Hansen, Michael Ryan,Amb, Chad M.,Risko, Chad,Subbiah, Jegadesan,Choudhury, Kaushik Roy,Mavrinskiy, Alexei,Pisula, Wojciech,Bredas, Jean-Luc,So, Franky,Muellen, Klaus,Reynolds, John R.
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p. 8944 - 8957
(2012/07/02)
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- Conjugated polymers based on C, Si and N-bridged dithiophene and thienopyrroledione units: Synthesis, field-effect transistors and bulk heterojunction polymer solar cells
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A series of low band-gap conjugated polymers (PDTC, PDTSi and PDTP) containing electron-rich C-, Si-, and N-bridged bithiophene and electron-deficient thienopyrroledione units were synthesized via Stille coupling polymerization. All these polymers possess a low-lying energy level for the highest occupied molecular orbital (HOMO) (as low as -5.44 eV). As a result, photovoltaic devices derived from these polymers show high open circuit voltage (Voc as high as 0.91 V). These rigid polymers also possess respectable hole mobilities of 1.50 × 10-3, 6.0 × 10 -4, and 3.9 × 10-4 cm2 V-1 s-1 for PDTC, PDTSi, and PDTP, respectively. The combined high V oc and good hole mobility enable bulk hetero-junction photovoltaic cells to be fabricated with relatively high power conversion efficiency (PCE as high as 3.74% for the PDTC-based device). The Royal Society of Chemistry 2011.
- Zhang, Yong,Zou, Jingyu,Yip, Hin-Lap,Sun, Ying,Davies, Josh A.,Chen, Kung-Shih,Acton, Orb,Jen, Alex K.-Y.
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p. 3895 - 3902
(2013/01/10)
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