- Co-sensitization of organic dyes for efficient dye-sensitized solar cells
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Novel cyanine dyes, in which a tetrahydroquinoline derivative is used as an electron donor and 1-butyl-5-carboxy-3, 3-dimethyl-indol-1-ium moiety is used as an electron acceptor and anchoring group, were designed and synthesized for application in dye-sensitized solar cells. The photovoltaic performance of these solar cells depends markedly on the molecular structure of the dyes in terms of the n-hexyl chains and the methoxyl unit. Retardation of charge recombination caused by the introduction of n-hexyl chains resulted in an increase in electron lifetime. As a consequence, an improvement of open-circuit photovoltage (V oc) was achieved. Also, the electron injection efficiencies were improved by the introduction of methoxyl moiety, which led to a higher short-circuit photocurrent density (Jsc). The highest average efficiency of the sensitized devices (η) was 5.6 % (Jsc=13.3 mA cm-2, Voc=606 mV, and fill factor FF=69.1 %) under 100 mW cm-2 (AM 1.5G) solar irradiation. All of these dyes have very high absorption extinction coefficients and strong absorption in a relatively narrow spectrum range (500-650 nm), so one of our organic dyes was explored as a sensitizer in co-sensitized solar cells in combination with the other two other existing organic dyes. Interestingly, a considerably improved photovoltaic performance of 8.2 % (Jsc=20.1 mA cm-2, Voc=597 mV, and FF=68.3 %) was achieved and the device showed a panchromatic response with a high incident photon-to-current conversion efficiency exceeding 85 % in the range of 400-700 nm. Sensitive dyes absorb it all: Co-sensitization of three spectrally complementary dyes on a TiO2 film in a well-designed sequence significantly improves the photovoltaic performance of the device, and an efficiency of 8.2 % is achieved. The devices demonstrate a panchromatic response with an incident photon-to-current conversion efficiency >80 % over the entire visible spectral region from 400 to 700 nm. Copyright
- Cheng, Ming,Yang, Xichuan,Li, Jiajia,Zhang, Fuguo,Sun, Licheng
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- Engineering of highly efficient tetrahydroquinoline sensitizers for dye-sensitized solar cells
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Four novel tetrahydroquinoline dyes by inserting isophorone and/or thiophene moieties as π bridge between the electron donating unit of substituted tetrahydroquinoline and the electron withdrawing unit of cyano carboxylic acid have been synthesized and successfully applied to dye-sensitized solar cells. Among them, DSCs sensitized by HYTIC, which shows the simplest molecular structure, exhibit improved efficiency of 7.0%. This by now is the highest efficiency for the reported tetrahydroquinoline sensitizers and comparable to the performance of N719-sensitized solar cells under the conditions employed here.
- Hao, Yan,Yang, Xichuan,Cong, Jiayan,Hagfeldt, Anders,Sun, Licheng
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scheme or table
p. 552 - 558
(2012/01/06)
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- Dye-sensitized solar cells based on a donor-acceptor system with a pyridine cation as an electron-withdrawing anchoring group
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New hemicyanine dyes (CM101, CM102, CM103, and CM104) in which tetrahydroquinoline derivatives are used as electron donors and N-(carboxymethyl)-pyridinium is used as an electron acceptor and anchoring group were designed and synthesized for dye-sensitized solar cells (DSSCs). Compared with corresponding dyes that have cyanoacetic acid as the acceptor, N-(carboxymethyl)-pyridinium has a stronger electron-withdrawing ability, which causes the absorption maximum of dyes to be redshifted. The photovoltaic performance of the DSSCs based on dyes CM101-CM104 markedly depends on the molecular structures of the dyes in terms of the n-hexyl chains and methoxyl. The device sensitized by dye CM104 achieved the best conversion efficiency of 7.0 % (Jsc=13.4 mA cm-2, Voc=704 mV, FF=74.8 %) under AM 1.5 irradiation (100 mW cm-2). In contrast, the device sensitized by reference dye CMR104 with the same donor but the cyanoacetic acid as the acceptor gave an efficiency of 3.4 % (Jsc=6.2 mA cm -2, Voc=730 mV, FF=74.8 %). Under the same conditions, the cell fabricated with N719 sensitized porous TiO2 exhibited an efficiency of 7.9 % (Jsc=15.4 mA cm-2, Voc=723 mV, FF=72.3 %). The dyes CM101-CM104 show a broader spectral response compared with the reference dyes CMR101-CMR104 and have high IPCE exceeding 90 % from 450 to 580 nm. Considering the reflection of sunlight, the photoelectric conversion efficiency could be almost 100 % during this region.
- Cheng, Ming,Yang, Xichuan,Li, Jiajia,Chen, Cheng,Zhao, Jianghua,Wang, Yu,Sun, Licheng
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supporting information
p. 16196 - 16202
(2013/02/23)
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- BENZAMIDIC COMPOUNDS HAVING FUNGICIDAL ACTIVITY AND RELATIVE USE
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The present invention relates to benzamidic compounds having general formula (I): wherein: Rx represents a halogen atom or a methyl group possibly substituted by fluorine atoms; R1, R2, R3, independently from each other, represent a C1- C3 alkyl group; R4 represents a hydrogen atom or a C1-C3 alkyl group; Ry represents a halogen atom, a C1-C4 alkyl group, a C1-C4 haloalkyl group, a C1-C4 alcoxy group, a C1-C4 haloalcoxy group; n represents an integer ranging of from 0 to 3. The present invention also relates to the use of the above benzamidic compounds for the control of fungi, bacteria and phytopathogenic viruses of agricultural crops.
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Page/Page column 15
(2010/12/01)
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- Synthesis and characterization of poly(1,3-phenylene)-based polyradicals carrying cyclic aminoxyls
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The synthesis and magnetic properties of poly(2,2,4,4-tetramethyl-N-yloxy-1,4-dihydro-2H-3,1-benzoxazine-6,8- diyl-1,3-phenylene) (4) are described. Polyradical 4 was prepared by the Pd-catalyzed cross-coupling reaction of 6,8-dibromo-2,2,4,4-tetramethyl-1,4-dihydro-2H-3,1-benzoxazine and bis(trimethylene) 1,3-phenylenediboronate, followed by oxidation with m-chloroperoxybenzoic acid. The number average molecular weights of 4 determined by SEC (size exclusion chromatography) were ~4120 (15 repeating units), and the spin concentrations determined by EPR were up to 0.75 spin per repeating unit. The EPR spectrum of 4 in a toluene glass matrix showed the ΔMs=2 forbidden transition at g=4.0. A Curie plot of the ΔMs=2 signal intensity vs. 1/T gave a straight line, suggesting that the polyradical is in a triplet ground state or a nearly degenerate singlet-triplet state.
- Oka, Hiroyuki,Tamura, Tomoki,Miura, Yozo,Teki, Yoshio
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p. 1364 - 1369
(2007/10/03)
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- Nitrogen-containing compound
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A novel nitrogen-containing compound capable of preventing hardening of blood vessels by controlling formation of peroxide lipids in cell membranes, which is valuable as an anti-arteriosclerotic agent, is disclosed.
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- Nitrothiazolyl-monoazo-2,2,4-trimethyl-1,2,3,4-tetrahydroquinoline compounds for polyester
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A monoazo compound of the formula, STR1 wherein X is hydrogen atom or lower alkyl group; Z is hydrogen atom, halogen atom, alkyl group, acylamino group, benzoylamino group or alkylsulfonylamino group; R1, R2, R3 and R4 independently are hydrogen atom or alkyl group, provided that R1, R2, R3 and R4 cannot simultaneously be hydrogen atoms; and R5 is hydrogen atom, alkyl group, substituted alkyl group, alkenyl group, cycloalkyl group, aralkyl group or phenyl group.
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