- Thermally cross-linkable hyperbranched polymers containing triphenylamine moieties: Synthesis, curing and application in light-emitting diodes
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This paper demonstrates synthesis of hyperbranched polymers (HTP and HTPOCH3), containing triphenylamine moieties in main chain and thermally cross-linkable periphery or terminal vinyl groups, and application as hole-transporting layer (HTL) in
- Yu, Juin-Meng,Chen, Yun
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- Dendron engineering in self-host blue iridium dendrimers towards low-voltage-driving and power-efficient nondoped electrophosphorescent devices
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Dendron engineering in self-host blue Ir dendrimers is reported to develop power-efficient nondoped electrophosphorescent devices for the first time, which can be operated at low voltage close to the theoretical limit (Eg/e: corresponding to the optical bandgap divided by the electron charge). With increasing dendron's HOMO energy levels from B-POCz to B-CzCz and B-CzTA, effective hole injection is favored to promote exciton formation, resulting in a significant reduction of driving voltage and improvement of power efficiency. Consequently, the nondoped device of B-CzTA achieves extremely low driving voltages of 2.7/3.4/4.4 V and record high power efficiencies of 30.3/24.4/16.3 lm W?1 at 1, 100 and 1000 cd m?2, respectively. We believe that this work will pave the way to the design of novel power-efficient self-host blue phosphorescent dendrimers used for energy-saving displays and solid-state lightings.
- Wang, Yang,Wang, Shumeng,Ding, Junqiao,Wang, Lixiang,Jing, Xiabin,Wang, Fosong
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- Redox- And protonation-induced fluorescence switch in a new triphenylamine with six stable active or non-active forms
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The synthesis, photophysical and electrochemical properties as well as theoretical calculation studies of a newly designed triphenylamine derivative are described. This original compound displays one neutral form, three oxidized forms, and two protonated
- Quinton, Cassandre,Alain-Rizzo, Valrie,Dumas-Verdes, Ccile,Miomandre, Fabien,Clavier, Gilles,Audebert, Pierre
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- Organic small molecule hole injection/transport material and preparation method and application thereof
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The invention belongs to the technical field of organic small molecule hole injection/transport materials, and discloses an organic small molecule hole injection/transport material and a preparation method and application thereof. A structural formula of the organic small molecule hole injecting/transporting material is as shown in the specification, wherein Ar1, Ar2 and Ar3 are independently unsubstituted benzene ring, fused ring or spiro ring aromatic hydrocarbons, or independently benzene ring, fused ring or spiro ring aromatic hydrocarbons substituted by an alkyl group, an alkoxy group oran alkylthio group with a carbon atom number of 1-6 respectively, and a carbon atom number of the benzene ring, fused ring or spiro ring aromatic hydrocarbons is 6-40. A plurality of non-planar structure arylamine units are adopted, and methoxy end groups are introduced, so that the material has high thermal stability, high glass transition temperature, high HOMO energy level, high hole mobility and good solubility, and has important application prospects in optoelectronic devices.
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Paragraph 0065; 0069-0071; 0109; 0113-0115
(2019/11/14)
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- Dopant-Free Hole-Transporting Polymers for Efficient and Stable Perovskite Solar Cells
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A series of novel polymers (P1-P6) derived from the combination of different units (including thiophene, triarylamine, and spirobifluorene) were successfully synthesized, completely characterized, and used as hole-transporting materials (HTMs) for perovskite solar cells (PSCs). Solar cells with some of these materials as HTMs showed very good performances of almost 13% (12.75% for P4 and 12.38% for P6) even without additives, and devices based on these new HTMs show relatively improved stability against temperature compared to those based on PTAA. The presence of dopant additives has been linked to long-term degradation, which is the main barrier to the large-scale commercialization of this innovative type of solar cell. Obtaining efficient PSCs without using dopants could represent a further step toward improvement of long-term stability and thus their introduction into the market.
- Valero, Silvia,Collavini, Silvia,V?lker, Sebastian F.,Saliba, Michael,Tress, Wolfgang R.,Zakeeruddin, Shaik M.,Gr?tzel, Michael,Delgado, Juan Luis
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p. 2243 - 2254
(2019/03/19)
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- Feasible energy level tuning in polymer solar cells based on broad band-gap polytriphenylamine derivatives
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A series of versatile broad band-gap alternating copolymers (P1, P2, P3 and P4) based on triphenylamine (TPA) and benzofurazan derivatives, differing in the substituted groups [-OC8H17, -C8H17, -CF3, -(CF3)2] in their triphenylamine units, were designed and synthesized by Suzuki polycondensation. The relationships between the substituted groups in TPA and the highest occupied molecular orbital (HOMO) energy levels, as well as the open circuit voltages (Vocs), were investigated in detail. The HOMO levels of these four polymers decreased sequentially when the substituted groups shifted from electron-donating groups [-OC8H17, -C8H17] to electron-withdrawing groups [-CF3, -(CF3)2], which led to the successive increase in Vocs of the polymer solar cells (PSCs) based on these polymers. Through the characterization of photovoltaic performance, the highest Voc, which reached up to 1.00 V, was achieved by the polymer with bis(trifluoromenthyl) substituted group (P4), which is one of the highest Voc values based on polytriphenylamine derived polymers for PSCs. Among these polymers, the one with octyl side chain (P2) showed the best photovoltaic performance with the highest short circuit current density (Jsc) and fill factor (FF), giving a Jsc of 4.84 mA cm-2, FF of 50%, Voc of 0.80 V and power conversion efficiency (PCE) of 2.22%.
- Zhang, Bin,Chen, Guiting,Xu, Jin,Hu, Liwen,Yang, Wei
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p. 402 - 412
(2016/01/12)
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- C-N cross-coupling reaction catalysed by reusable CuCr2O4 nanoparticles under ligand-free conditions: A highly efficient synthesis of triarylamines
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A convenient, efficient and ligand-free method for the C-N coupling reaction of anilines and aryl iodides was performed using CuCr2O4 nanoparticles. Copper chromite nanocatalyst improved the rate and facility of the synthesis of triarylamines. The heterogeneous catalyst was fully characterized by scanning electron microscopy, IR and X-ray diffraction techniques. Recyclability, excellent yields of products and short reaction times are the important advantages of this ligand-free procedure by using the CuCr2O4 nanoparticles. This journal is
- Safaei-Ghomi, Javad,Akbarzadeh, Zeinab,Khojastehbakht-Koopaei, Bahareh
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p. 28879 - 28884
(2015/04/14)
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- A convenient and efficient synthesis of triarylamine derivatives using CuI nanoparticles
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We report a simple and efficient method for the synthesis of triarylamine derivatives using copper iodide nanoparticles, 1,10-phenanthroline and potassium hydroxide. Copper iodide nanoparticles enhanced the rate and ease of reaction and exhibited a high influence in the efficient synthesis of various amine derivatives. The nanoparticles also increased the yields of products and decreased the reaction times in all cases. The heterogeneous mediator was fully characterized by scanning electron microscopy and X-ray diffraction techniques.
- Safaei-Ghomi, Javad,Akbarzadeh, Zeinab,Ziarati, Abolfazl
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p. 16385 - 16390
(2014/05/06)
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- Synthesis, electrochemical, and optical properties of low band gap homo- and copolymers based on squaraine dyes
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A broad series of monomeric and polymeric squaraines was synthesized to investigate the impact of electron-donating bridges, such as unsaturated triarylamine, carbazole, and saturated piperazine groups, on the spectroscopic and redox properties. These bridges were attached to both standard trans-indolenine squaraines and dicyanomethylene-substituted cis-indolenine squaraines. The conjugates were investigated by absorption, steady-state, and time-resolved fluorescence spectroscopy and cyclic voltammetry. While addition of the donors resulted in significant redshift of the absorption of the model compounds, hardly any further shift or broadening was observed for the copolymers. Also the redox properties remained nearly unchanged compared with the model dyes. In contrast, immense broadening and redshift was observed for homopolymers. This behavior is explained by mostly excitonic coupling of localized squaraine transitions. The increasing distance of the chromophores determined by the bridges led to a decrease of the exciton coupling energy. We also performed semiempirical CNDO/S2 calculations on AM1 optimized structures.
- Voelker, Sebastian F.,Dellermann, Theresa,Ceymann, Harald,Holzapfel, Marco,Lambert, Christoph
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p. 890 - 911
(2014/03/21)
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- Design of new tetrazine-triphenylamine bichromophores - Fluorescent switching by chemical oxidation
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Original new fluorescent and electroactive compounds have been prepared, which feature two different fluorescent groups linked through an oxygen atom spacer. We describe here the synthesis, photophysical and electrochemical properties and their interplay, and our theoretical calculations. These molecules are composed of two fluorophores, an electron-rich triphenylamine unit and an electron-poor tetrazine unit. Although the bichromophores are not fluorescent in the neutral state due to a photoinduced electron transfer from the triphenylamine unit to the tetrazine unit, one can restore the fluorescence by oxydation of the triphenylamine moiety. Thus, a redox-fluorescent switch has been realized. Tetrazine-triphenylamine bichromophores linked by an oxygen atom were designed and synthesized. Their photophysical and electrochemical properties were investigated. These dyads are nonfluorescent compounds in their neutral state because of phoinduced electron transfer. However, tetrazine fluorescence was restored by chemical oxidation (cation radical formation). Copyright
- Quinton, Cassandre,Alain-Rizzo, Valerie,Dumas-Verdes, Cecile,Clavier, Gilles,Miomandre, Fabien,Audebert, Pierre
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p. 1394 - 1403
(2012/04/17)
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- Hydrophilic poly(triphenylamines) with phosphonate groups on the side chains: Synthesis and photovoltaic applications
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Two triphenylamine-based homopolymers PTPA-EP and PTPA-PO 3Na2, comprising diethyl phosphonate and sodium phosphonate end groups on side chains, respectively, were synthesized. The UV-vis absorption and photoluminescence (PL) properties of the PTPA-EP and PTPA-PO3Na2 are mainly determined by the conjugated poly(triphenylamine) main chain. The PTPA-EP and PTPA-PO3Na 2 possess comparable HOMO levels of around -5.03 eV. The PTPA-EP, with better solubility than PTPA-PO3Na2 in hydrophilic solvents, was utilized as cathode interlayer to construct efficient bulk-heterojunction photovoltaic cells with a low bandgap poly(2,7-carbazole) (PCDTBT) as the polymer donor and [6,6]-phenyl C71-butyric acid methyl ester (PC71BM) as the acceptor. The work function of ITO was shifted to -4.3 eV by PTPA-EP, which matches well with the LUMO level of PC 71BM for good electron extraction. Inverted solar cells with a device configuration of ITO/PTPA-EP/active layer/MoO3/Al exhibited a power conversion efficiency (PCE) of 4.59%, which is a good efficiency among inverted solar cells with an organic interlayer on an ITO cathode. The PCE shows a 79% increase in comparison to that of a bare ITO cathode, though the efficiency is lower than 5.13% for an inverted solar cell with an inorganic ZnO interlayer on ITO. Moreover, a conventional solar cell with a device configuration of ITO/PEDOT:PSS/active layer/PTPA-EP/Al could show a better PCE of 5.27%. The results indicate that PTPA-EP is a promising new cathode interlayer for high efficiency inverted and conventional solar cells.
- Xu, Xiaofeng,Zhu, Yongxiang,Zhang, Lianjie,Sun, Jiangman,Huang, Jun,Chen, Junwu,Cao, Yong
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p. 4329 - 4336
(2012/08/08)
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- Synthesis of novel triphenylamine-based conjugated polyelectrolytes and their application as hole-transport layers in polymeric light-emitting diodes
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Alternating triphenylamine-based copolymers poly[N-(4- sulfonatobutyloxyphenyl)-4,4′-diphenylamine-alt-1,4-phenylene] sodium salt (PTPOBS) and poly[N-(4-sulfonatophenyl)-4,4′-diphenylamine-alt-N-(p- trifluoromethyl)phenyl-4,4′-diphenylamine] sodium salt (PTFTS) were synthesized via palladium-catalyzed Suzuki coupling reaction. These polymers are soluble only in polar solvents, such as dimethyl sulfoxide (DMSO) and a mixed solvent of methanol and N,N-dimethyl formamide (DMF), rather than in non-polar solvents such as toluene and xylene. The electrochemical and photophysical properties of the resulted copolymers were investigated. The HOMO levels of the polymers (-5.08 eV for PTPOBS and -5.24 eV for PTFTS) were close to the work function of PEDOT. The relatively high-lying LUMO levels (-2.21 eV for PTPOBS and -2.24 eV for PTFTS) revealed that they had good electron-blocking capabilities. Devices with a PTPOBS or PTFTS layer inserted between ITO or PEDOT and of red and green-emitting polymers showed lower turn-on voltages and enhanced efficiency compared with the reference devices composed of bare ITO or ITO/PEDOT as anode. These polymers can be used as an independent hole-transport/electron-blocking layer or in combination with a PEDOT layer for fabrication of multilayer devices without intermixing with the subsequent EL layer by solution processing in full-color display applications. The Royal Society of Chemistry 2006.
- Shi, Wei,Fan, Suqin,Huang, Fei,Yang, Wei,Liu, Ransheng,Cao, Yong
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p. 2387 - 2394
(2008/01/27)
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- Concerted proton-electron transfer in the oxidation of hydrogen-bonded phenols
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Three phenols with pendant, hydrogen-bonded bases (HOAr-B) have been oxidized in MeCN with various one-electron oxidants. The bases are a primary amine (-CPh2NH2), an imidazole, and a pyridine. The product of chemical and quasi-reversible electrochemical oxidations in each case is the phenoxyl radical in which the phenolic proton has transferred to the base, .OAr-BH+, a proton-coupled electron transfer (PCET) process. The redox potentials for these oxidations are lower than for other phenols, predominately from the driving force for proton movement. One-electron oxidation of the phenols occurs by a concerted proton-electron transfer (CPET) mechanism, based on thermochemical arguments, isotope effects, and ΔΔG?/ΔΔGo. The data rule out stepwise paths involving initial electron transfer to form the phenol radical cations [.+HOAr-B] or initial proton transfer to give the zwitterions [-OAr-BH+]. The rate constant for heterogeneous electron transfer from HOAr-NH2 to a platinum electrode has been derived from electrochemical measurements. For oxidations of HOAr-NH2, the dependence of the solution rate constants on driving force, on temperature, and on the nature of the oxidant, and the correspondence between the homogeneous and heterogeneous rate constants, are all consistent with the application of adiabatic Marcus theory. The CPET reorganization energies, λ = 23-56 kcal mol-1, are large in comparison with those for electron transfer reactions of aromatic compounds. The reactions are not highly non-adiabatic, based on minimum values of Hrp derived from the temperature dependence of the rate constants. These are among the first detailed analyses of CPET reactions where the proton and electron move to different sites.
- Rhile, Ian J.,Markle, Todd F.,Nagao, Hirotaka,DiPasquale, Antonio G.,Lam, Oanh P.,Lockwood, Mark A.,Rotter, Katrina,Mayer, James M.
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p. 6075 - 6088
(2007/10/03)
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- Poly-p-phenylene phosphine/polyaniline alternating copolymers: Electronic delocalization through phosphorus
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Phosphorus-containing poly(N-arylaniline)s and related polymer model compounds have been prepared. The spectroscopic and electronic properties of the materials were investigated via UV-vis-NIR spectroscopy and cyclic voltammetry. PPPP-PANI copolymers cont
- Jin, Zhou,Lucht, Brett L.
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p. 5586 - 5595
(2007/10/03)
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- Long-Lived Photoinduced Charge Separation and Redox-Type Photochromism on Mesoporous Oxide Films Sensitized by Molecular Dyads
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The photoinduced charge separation in three different assemblies composed of an electron donor D and a chromophore sensitizer S adsorbed on nanocrystalline TiO2 films (D-S|TiO2) was investigated. In all of the systems, the sensitizer was a ruthenium(II) bis-terpyridine complex anchored to the semiconductor surface by a phosphonate group. In two of the assemblies, the donor was a 4-(N,N-di-p-anisylamino) phenyl group linked to the 4′ position of the terpyridine, either directly (dyad D1-S) or via a benzyl ether interlocking group (dyad D2-S). In the third system, the sensitizer and the donor (3-(4-(N,N-di-p-anisylamino)phenoxy)-propyl-1-phosphonate) were coadsorbed on the surface ((D3+S)|TiO2). Laser flash photolysis showed that the photoinduced charge separation process follows the sequence D-S*|TiO2 1→ D-S+|(e-)TiO2 2→ D+-S|(e-)TiO2 3→ D-S|TiO2 Resonance Raman spectroscopy indicates that in the excited assemblies D2-S*|TiO2 and (D3+S*)|TiO2, one electron is promoted from the metal center to the terpyridine ligand linked to the semiconductor, whereas in the system D1-S*|TiO2 the excited electron is located on the ligand linked to the donor. The quantum yield of charge separation (steps 1 and 2) was found to be close to unity for the two former assemblies but only 60% for the latter one. In all three cases, the electron injection was very fast (++S)|(e-)TiO2, as in the model system S+|(e-)TiO2; it was 30 μs in D1+-S|(e-)TiO2 and 300 μs in D2+-S|(e-)TiO2. Electrodes made of any of the surface-confined dyads on conducting glass display a strong redox-type photochromism. When a positive potential (+0.5 V vs NHE) is applied to the electrode, charge recombination (step 3) is blocked. As a result, the visible absorption spectrum of the electrode changes, due to the appearance of the absorption feature of the oxidized donor (λmax = 730 nm). Return to the reduced state is achieved by electron injection through the conduction band of the TiO2 under forward bias (-0.5 V). None of the assemblies D1-S|TiO2 and D2-S|TiO2 gave better photovoltaic performances than the model system S|TiO2. This was attributed in the first case to the low injection efficiency and, in the second case, to an additional short-circuiting pathway constituted by the charge percolation inside the molecular monolayer and to the underlying conducting glass, as previously observed with monolayers of the donor D3 (Bonhote, P.; Gogniat, E.; Tingry, S.; Barbe, C.; Vlachopoulos, N.; Lenzmann, F.; Comte, P.; Graetzel, M. J. Phys. Chem. B 1998, 102, 1498-1507).
- Bonhote, Pierre,Moser, Jacques-E.,Humphry-Baker, Robin,Vlachopoulos, Nicolas,Zakeeruddin, Shaik M.,Walder, Lorenz,Graetzel, Michael
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p. 1324 - 1336
(2007/10/03)
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