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1.
A series of conjugated (poly{N‐(2‐ethylhexyl)‐3,6‐carbazole–vinylene‐alt‐[(2,5‐bisphenyl)‐1,3,4‐oxadiazole]}) and nonconjugated (poly{N‐(2‐ethylhexyl)‐3,6‐carbazole–vinylene‐alt‐[(2,5‐bisphenol)‐1,3,4‐oxadiazole]}) and poly{9,9‐dihexyl‐2,7‐fluorene–vinylene‐alt‐[(2,5‐bisphenol)‐1,3,4‐oxadiazole]}) polymers containing oxadiazole and carbazole or fluorene moieties in the polymer backbone were synthesized with a multiple‐step procedure. The properties of the polymers, including the photophysical and electrochemical characteristics, could be fine‐tuned by adjustment of the components or structures in the polymer chains. The polymers were used to examine the hole‐injection/transport behavior as hole‐injection/hole‐transport layers in double‐layer indium tin oxide (ITO)/polymer/aluminum tris(8‐hydroxyquinoline)/LiF/Al devices by the determination of their energy levels. The effects of the polymers in these devices on the charge‐transport behavior were compared with a control device fabricated with poly(ethylenedioxythiophene) (PEDOT)–poly(styrene sulfonate) (PSS). Devices containing the synthesized polymers showed comparable adhesion to the ITO anode and good hole‐injection/transport performance. In addition, they exhibited higher electroluminescence over an identical range of current densities than the control device. This was attributed to the prevention of radiative exciton quenching caused by the PEDOT–PSS interfaces and the improvement of electron/exciton blocking due to the higher electron affinity of the synthesized polymers. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011 相似文献
2.
For plastic (opto)electronic devices such as light‐emitting diodes (LEDs), photovoltaic (PV) cells and field‐effect transistors (FETs), the processes of charge (hole/electron) injection, charge transport, charge recombination (exciton formation), charge separation (exciton diffusion and dissociation) and charge collection are critical to enhance their performance. Most of these processes are relevant to nanoscale and interfacial phenomena. In this review, we highlight the state‐of‐the‐art developments of interface‐tailored and nanoengineered polymeric materials to optimize the performance of (opto)electronic devices. These include (1) interfacial engineering of anode and cathode for polymer LEDs; (2) nanoengineered (C60 and inorganic semiconductor nanoparticles) π‐conjugated polymeric materials for PV cells; and (3) polymer and monolayer dielectrics/interfaces for FETs and light‐emitting and nano‐FETs. Copyright © 2009 Society of Chemical Industry 相似文献
3.
In order to observe the effects of the substitution of electronegative flourine with aromatic groups in oligo(p ‐phenylenevinylene) compounds on their packing, morphology, and charge carrier mobility, we have synthesized napthol‐substituted oligo(p ‐phenylenevinylene) compounds and examined their solubility, redox properties, thin film morphologies, and charge carrier properties. To date, very few examples of conjugated oligomers bearing napthol side groups have been reported in the literature. After annealing at 150 °C, the mobility of S1, S2, and S3 was 4.0 × 10?2 cm2 V?1 s?1, 1.2 × 10?2 cm2 V?1 s?1, and 2.6 × 10?3 cm2 V?1 s?1, respectively. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 44825. 相似文献
4.
BACKGROUND: Hole‐transport layers (HTLs) play a crucial role in multilayer polymeric light‐emitting diodes (PLEDs) for the achievement of satisfactory device performance. During the fabrication of multilayer PLEDs via solution processing, the fabricated HTLs encounter the risk of erosion during the film‐forming process of subsequent emitting layers (EMLs). In contrast to the widely investigated crosslinkable HTLs, much less attention has been paid to the preparation of polar‐solvent‐soluble HTLs, which is a straightforward solution to overcome the interfacial mixing between HTLs and EMLs during solution processing. RESULTS: Alternating triphenylamine‐ and fluorene‐based anionic copolymer poly[9,9‐bis(4′‐sulfonatobutyl)fluorene‐alt‐N‐(p‐trifluoromethyl)phenyl‐4,4′‐diphenylamine]sodium salt (PFT‐CF3) was synthesized via a palladium‐catalyzed Suzuki coupling reaction. This polyelectrolyte is soluble only in polar solvents such as methanol, dimethylformamide and dimethylsulfoxide rather than in non‐polar solvents such as toluene, chloroform and xylene. The relatively high HOMO (?5.22 eV) and LUMO (?2.26 eV) levels of this polymer endow it simultaneously with good hole‐transporting and electron‐blocking capabilities. The performance of red‐, green‐ and blue‐emitting devices utilizing this polyelectrolyte as HTL was investigated. CONCLUSION: The anionic conjugated polyelectrolyte based on triphenylamine and fluorene, PFT‐CF3, can serve as a promising hole‐transporting/electron‐blocking layer in multilayer PLEDs. Copyright © 2009 Society of Chemical Industry 相似文献
5.
Su‐Yang Zhang Fan Kong Rong Sun Ren‐Kuan Yuan Xi‐Qun Jiang Chang‐Zheng Yang 《应用聚合物科学杂志》2003,89(10):2618-2623
A novel copolymer, poly{[2,5‐diphenylene‐1,3,4‐oxadiazole‐vinylene]‐alt‐[2‐methoxy‐5‐(2‐ethylhexyloxy)‐1,4‐phenylenevinylene]}(MEH‐OPPV) containing a high‐electron‐affinity unit of aromatic oxadiazole in the main chain is synthesized through the Wittig condensation reaction. The obtained copolymer is easily soluble in conventional organic solvents. The structure of the copolymer was characterized by Fourier transform infrared, 1H nuclear magnetic resonance, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and ultraviolet‐visible and photoluminescence spectroscopy. The TGA result indicates that the copolymer has very high thermal stability (stable up to 310°C in nitrogen), while DSC investigation demonstrates that the glass transition temperature (Tg) is 143°C, which might be a merit for the long‐life operation of light‐emitting devices. The absorption spectrum of film sample of the copolymer reveals two peaks at 310 and 370 nm, respectively, and the edge absorption corresponds to a band gap of 2.46 eV. A single‐layer light‐emitting diode device ITO/MEH‐OPPV/Al is successfully fabricated. The device emits visible yellowish‐green light above the bias voltage of 4.0 V under ambient condition. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2618–2623, 2003 相似文献
6.
A general overview of the optoelectronic properties of π‐conjugated polymers is presented. Two types of polymer are discerned: interchangeable structures of the same energy (degenerate), such as polyacetylene; and non‐degenerate polymers, such as poly(para‐phenylene). The band structures of degenerate and non‐degenerate polymers are related to their conductivities in doped and non‐doped states. In both cases, disorder and impurities play an important role in conductivity. Polarons, bipolarons and excitons are detailed with respect to doping and charge transfers. Given the fibrillic nature of these materials, the variable range hopping (VRH) law for semiconducting polymers is modified to account for metallic behaviours. Optoelectronic properties—electroluminescence and photovoltaic activity—are explained in terms of HOMO and LUMO bands, polaron‐exciton and charge movement over one or more molecules. The properties of H‐ or J‐type aggregates and their effects on transitions are related to target applications. Device structures of polymer light‐emitting diodes are explicitly linked to optimising polaron recombinations and overall quantum efficiencies. The particularly promising use of π‐conjugated polymers in photovoltaic devices is discussed. Copyright © 2004 Society of Chemical Industry 相似文献
7.
Guanglong Wu Chunhe Yang Benhu Fan Bin Zhang Xiaomin Chen Yongfang Li 《应用聚合物科学杂志》2006,100(3):2336-2342
A photo‐crosslinkable polymer, poly[2,7‐(9,9‐dioctylfluorene)‐co‐2,7‐(9‐hexyl‐9‐(2‐acrylate ethyl)‐9H‐fluorene)] (P3), was synthesized and the photo‐crosslinkable acrylate groups were introduced into the side‐chains of the polyfluorene derivative after its polymerization. This method avoids the possible crosslinkage of the crosslinkable groups on the monomers during polymerization in the traditional synthesis route by the polymerization of the monomers with the crosslinkable side‐chains. The soluble and processable polymer P3 could be crosslinked via the acrylate groups in its side‐chains upon exposure to UV light in nitrogen atmosphere. The crosslinking was confirmed by IR spectroscopy: the IR peak of C?C bond at 1635 cm?1 decreased and that of the vinyl C? H bond at 742 cm?1 disappeared after the UV exposure. The absorption spectra of P3 remain unchanged after crosslinking, but a longer wavelength emission at 517 nm appeared in the photoluminescent and electroluminescent spectra of the crosslinked P3, which could be attributed to the formation of keto defects during the photo crosslinking. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2336–2342, 2006 相似文献
8.
Two novel phenyl‐substituted poly(p‐phenylene vinylene) derivatives, poly{2‐[3′,4′‐(2″‐ethylhexyloxy)(3″,7″‐dimethyloctyloxy)benzene]‐1,4‐phenylenevinylene} (EDP‐PPV) and poly{2‐[3′,4′‐(2″‐ethylhexyloxy)(3″,7″‐dimethyloctyloxy)benzene]‐5‐methoxy‐1,4‐phenylenevinylene} (EDMP‐PPV), and their copolymer, poly{2‐[3′,4′‐(2″‐ethylhexyloxy)(3″,7″‐dimethyloctyloxy)benzene]‐1,4‐phenylene‐vinylene‐co‐2‐[3′,4′‐(2″‐ethylhexyloxy)(3″,7″‐dimethyloctyloxy)benzene]‐5‐methoxy‐1,4‐phenylenevinylene} (EDP‐co‐EDMP‐PPV; 4:1, 1:1, and 1:4), were successfully synthesized according to the Gilch route. The structures and properties of the monomers and the resulting conjugated polymers were characterized with 1H‐NMR, 13C‐NMR, elemental analysis, gel permeation chromatography, thermogravimetric analysis, ultraviolet–visible absorption spectroscopy, and photoluminescence and electroluminescence (EL) spectroscopy. The EL polymers possessed excellent solubility in common solvents and good thermal stability with a 5% weight loss temperature of more than 380°C. The weight‐average molecular weights and polydispersity indices of EDP‐PPV, EDMP‐PPV, and EDP‐co‐EDMP‐PPV were 1.40–2.58 × 105, and 1.19–1.52, respectively. Double‐layer light‐emitting diodes with the configuration of indium tin oxide/polymer/tris(8‐hydroxyquinoline)aluminum/Al devices were fabricated, and EDP‐co‐EDMP‐PPV (1:1) showed the highest EL performance and exhibited a maximum luminance of 1050 cd/m2 at 19.5 V. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 1259–1266, 2005 相似文献
9.
Excimer and electromer suppression of tetraphenylsilane‐derivative‐based blue polymer light‐emitting devices (PLEDs) was investigated. Tetraphenylsilane with a rigid bulky structure certainly but not completely suppressed excimer formation among polymer‐chain segments. A poor solvent, toluene, resulted in excimer formation in the solid film during the spin‐coating process, which could not be suppressed by the incorporation of a bulky moiety onto the polymer backbone. In addition, electromers or electroplexes formed by the strong interaction between the oxadiazole and diphenyl(4‐tolyl)amine groups could not be prevented by the tetraphenylsilane moiety. The influences of the bulky moiety, bipolar unit, and device fabrication conditions on the suppression of excimers or electromers in PLEDs are discussed in detail. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 相似文献
10.
Mukundan Thelakkat 《大分子材料与工程》2002,287(7):442-461
Recent developments in the synthesis and application of hole conducting oligomeric and polymeric triarylamines are reviewed. The materials are classified as Star‐shaped molecules, Spiros and dendrimers, Side‐chain polymers, and Main‐chain polymers and copolymers. This paper concentrates on the research results of our group on the synthesis of a variety of such compounds, their structure‐property relationship and their application in devices like organic light emitting diodes, solar cells and photorefractive systems. The thermal properties and electronic properties of these compounds were varied by changing the chemical structure and nature of substituents. In the case of low molecular weight star‐shaped molecules the glass transition temperature could be increased to above 140°C by suitable structural design. Similarly, for polymeric triarylamines the variation of glass transition temperature was achieved over a wide range from 92 to 237°C. This is especially necessary for the wide spectrum of applications of these materials as hole conductors in low‐Tg photorefractive composites to high‐Tg materials in OLEDs. Moreover, the electronic energy levels and the band gap in these compounds can be manipulated to optimize the hole injection or electron transfer or emission properties or even photocurrent generation to make them suitable for various applications. Especially, the concept of copolymerization with other functional monomers results in multifunctional copolymers with good hole injection and transport properties. The polymer networks involving triarylamine structures are not included in this Review, because this constitutes the subject‐matter of insoluble hole transport materials and will be published elsewhere. 相似文献
11.
Zhan'ao Tan Rupei Tang Erjun Zhou Youjun He Chunhe Yang Fu Xi Yongfang Li 《应用聚合物科学杂志》2008,107(1):514-521
A copolymer of dendronized poly(p‐phenylene vinylene) (PPV), poly{2‐[3′,5′‐bis (2′‐ethylhexyloxy) bnenzyloxy]‐1,4‐phenylene vinylene}‐co‐poly[2‐methoxy‐5‐(2′‐ethylhexyloxy)‐1,4‐phenylene vinylene] (BE‐co‐MEH–PPV), was synthesized with the Gilch route to improve the electroluminescence and photovoltaic properties of the dendronized PPV homopolymer. The polymer was characterized by ultraviolet–visible absorption spectroscopy, photoluminescence spectroscopy, and electrochemical cyclic voltammetry and compared with the homopolymers poly{2‐[3′, 5′‐bis(2‐ethylhexyloxy) benzyloxy‐1,4‐phenylene vinylene} (BE–PPV) and poly[2‐methoxy‐5‐(2′‐ethylhexyloxy)‐1,4‐phenylenevinylene] (MEH–PPV). Polymer light‐emitting diodes based on the polymers with the configuration of indium tin oxide (ITO)/poly(3,4‐ethylene dioxythiophene) : poly(styrene sulfonate) (PEDOT : PSS)/polymer/Ca/Al were fabricated. The electroluminescence efficiency of BE‐co‐MEH–PPV reached 1.64 cd/A, which was much higher than that of BE–PPV (0.68 cd/A) and a little higher than that of MEH–PPV (1.59 cd/A). Photovoltaic properties of the polymer were studied with the device configuration of ITO/PEDOT : PSS/polymer : [6,6J‐phenyl‐C61‐butyric acid methyl ester] (PCBM)/Mg/Al. The power conversion efficiency of the device based on the blend of BE‐co‐MEH–PPV and PCBM with a weight ratio of 1 : 3 reached 1.41% under the illumination of air mass 1.5 (AM1.5) (80 mW/cm2), and this was an improvement in comparison with 0.24% for BE–PPV and 1.32% for MEH–PPV under the same experimental conditions. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 相似文献
12.
13.
Summary: We demonstrate the use of polyisobutene (PIB) in a glass encapsulation method suitable for organic devices. The PIB viscosity at environmental temperatures provides a fast and non‐aggressive passivant layer formation method for device protection with glass. Due to its fully aliphatic character, PIB is suitable for passivating organic light‐emitting and photovoltaic devices. The observed preservation of encapsulated Ca films demonstrates the PIB suitability for air‐unstable metals passivation. Stable I(V) characteristics and increased operational lifetime were observed in PIB‐encapsulated organic devices. This encapsulation method is cheap, simple, and dispenses intensive equipment use, so that it is appropriate even for laboratories with restricted experimental facilities.
Setup used for Ca samples testing. The right Ca contact was encapsulated with PIB and a glass cover plate (dashed square). The electrical diagram of the apparatus used to obtain the resistance behavior is also shown. 相似文献
14.
《大分子材料与工程》2017,302(11)
π‐Conjugated polymers suffer from low quantum yields (QYs) due to chain–chain interactions. Furthermore, their emission in solid films is significantly quenched due to aggregation leading further decrease in QY. These are the two main issues of these materials hampering their widespread use in optoelectronic devices. To address these issues, here the backbone of poly(9,9′‐bis(6″‐(N ,N ,N‐trimethylammonium)hexyl)fluorene‐alt‐co‐thiophenelene) is isolated by threading with cucurbit[7 ]uril (CB7). Subsequently, the conjugated polyrotaxanes are incorporated into organic crystalline matrices to obtain highly efficient color‐converting solids suitable for solid‐state lighting. Upon threading the polymer backbone with CB7s, although the QY of the resulting polyrotaxane in solution state increases, the quenching problem in their solid state is not completely tackled. To solve this problem, these conjugated polyrotaxanes are embedded into various crystalline matrices and their remarkably high QYs (>50%) in the solution are successfully maintained in the solid state. To demonstrate the suitability of these aforementioned materials for solid‐state lighting, a proof‐of‐concept light‐emitting diode is constructed by employing their powders as color converters. 相似文献
15.
Two new poly(p‐phenylenevinylene) (PPV) derivatives containing oxadiazole moiety (OXA‐PPV1 and OXA‐PPV2) were synthesized by the Wittig condensation polymerization reaction. Their thermal and light‐emitting properties were investigated. The single‐ and triple‐layer electroluminescent (EL) devices with configurations of ITO/polymer/Al and ITO/polymer/OXD‐7/Alq3/Al were fabricated. They exhibited blue emission at 470 nm for OXA‐PPV1 and green emission at 560 nm for OXA‐PPV2. The turn‐on voltages of triple‐layer device were 11 V for OXA‐PPV1 and 8 V for OXA‐PPV2. The triple‐layer EL devices showed much better performance than did the single‐layer devices. The spectra indicated energy transfer occurred from segments of side chain to polymer backbone. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 422–428, 2002 相似文献
16.
A white emitting poly(phenylenevinylene) 总被引：1，自引：0，他引：1
Carmela Martinelli Umberto Giovanella Antonio Cardone Silvia Destri Gianluca M. Farinola 《Polymer》2014
A white emitting copolymer with the polyphenylenevinylene (PPV) structure is obtained via the Stille cross-coupling reaction. Substitution of hydrogen atoms with fluorine atoms on the vinylene units of poly(1,4-dialkoxyphenylenevinylene) shifts the emission from orange-red to blue. White emission is obtained by combining dialkoxyphenylenedifluorovinylene and dialkoxyphenylenevinylene units in proper ratio. The two complementary emitters are obtained separately by Stille polymerization reaction. Then, the two reaction mixtures are combined without purification in different ratios and further reacted in similar experimental conditions. A white luminescent material is obtained using 99/1 mixing ratio. OLED devices fabricated with this copolymer shows near-white emission with CIE (0.30, 0.40) and excellent stability in the range 10–200 cd/m2. 相似文献
17.
A polyether, poly[(2,5‐dimethylene‐1,3,4‐oxadiazole)dioxy‐1,4‐phenylene‐1,2‐ethenylene‐1,4‐phenylene‐1,2‐ethenylene‐1,4‐phenylene], based on short alternating conjugated oxadiazole units, has been synthesized, which is a kind of PPV derivative that emits blue light. The resulting polymer is fairly soluble in chloroform. The synthesized polymer shows a UV–visible absorbency maximum wavelength around 310 nm in solution. The photoluminescence maximum wavelength for the resulting polymer appears around 470 nm. The polymer also exhibits good thermal stability up to 300°C under N2 atmosphere. It is also observed that the onset temperature of thermal decomposition is as high as 355°C. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 2682–2686, 2002 相似文献
18.
Kai‐Fang Cheng Mei‐Hsiu Lai Chih‐Feng Wang Wen‐Chung Wu Wen‐Chang Chen 《应用聚合物科学杂志》2009,112(4):2094-2101
New donor–acceptor conjugated copolymers called poly}2,7‐(9,9′‐dihexylfluorene)‐co‐5,10‐[pyrazino(2,3‐g)quinoxaline]{s or PFPQs [where F represents the 2,7‐(9,9′‐dihexylfluorene) moiety and PQ represents the 5,10‐(pyrazino[2,3‐g]quinoxaline) moiety], synthesized by the palladium‐catalyzed Suzuki coupling reaction, are reported. The PQ contents in the PFPQ copolymers were 0.3, 1, 5, and 50 mol %, and the resulting copolymers were named PFPQ0.3, PFPQ01, PFPQ05, and PFPQ50, respectively. Absorption spectra showed a progressive redshift as the PQ acceptor content increased. The relatively small optical band gap of 2.08 eV for PFPQ50 suggested strong intramolecular charge transfer (ICT) between the F and PQ moieties. The photoluminescence emission peaks of the PFPQ copolymer films also exhibited a large redshift with enhanced PQ contents, ranging from 551 nm for PFPQ0.3 to 592 nm for PFPQ50. However, the PFPQ copolymer based electroluminescence (EL) devices showed poor device performances probably due to the strong confinement of the electrons in the PQ moiety or significant ICT. This problem was resolved with a binary blend of poly[2,7‐(9,9‐dihexylfluorene)] (PF) and PFPQ with a volume ratio of 95/5 (BPQ05). Multiple emission peaks were observed at 421, 444, 480, 516, and 567 nm in the BPQ05‐based EL devices because the low PQ content led to incomplete energy transfer. The Commission Internationale de L'Eclairage 1931 coordinates of the BPQ05‐based EL device were (0.31, 0.32), which were very close to the standard white emission of (0.33, 0.33). Furthermore, the maximum luminescence intensity and luminescence yield were 524 cd/m2 and 0.33 cd/A, respectively. This study suggested that a pure white light emission was achieved with the PFPQ copolymers or PF/PFPQ blends through the control of the energy transfer between F and PQ. Such PFPQ copolymers or PF/PFPQ blends would be interesting for electronic and optoelectronic devices. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 相似文献
19.
We present the electrical and optical characteristics of a single‐ion transport light‐emitting electrochemical cell (SLEC) based on poly(p‐phenylene vinylene) (PPV) derivative containing aryl‐substituted oxadiazole in the backbone (MEH‐OPPV). Ionized polyurethane–poly(ethylene glycol) (PUI) used as polymer electrolyte is introduced into the active layer of the SLEC. The turn‐on voltage of the SLEC is about 3 V according to its current density–voltage (J–V) characteristics. The response time of the SLEC is less than 10 ms, lower than that of normal LECs by two orders of magnitudes roughly. The reasons of the quick response for the SLEC are discussed in the article. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4253–4255, 2006 相似文献
20.
Two novel luminescent block copolymers (CE–PPV and CE–DMPPV), containing alternating distyrylbenzene [poly(phenylene vinylene) model oligomer] as light‐emitting units and crown‐ether segments as ionic conductive and spacer units were synthesized by use of a Wittig reaction between the dialdehyde monomer and 1,4‐xylylene‐bis(triphenylphosphonium bromide) or 1,4‐bis(triphenylphosphoniomethyl)‐2,5‐dimethoxybenzene dichloride. The synthesized polymers were characterized with FTIR, 1H‐NMR, UV–Vis, differential scanning calorimetry, and gel permeation chromatography. The number‐average molecular weights were 6896 with a polydispersity index of 1.75 for CE–PPV, and 9301 with a polydispersity index of 2.474 for CE–DMPPV, respectively. The decomposition temperatures and the glass‐transition temperatures were in the range of 395–411°C and 75–77°C, respectively. The electrochemical properties of the copolymers were evaluated and the highest occupied molecular orbital and the lowest unoccupied molecular orbit energy levels of the copolymers were estimated by cyclic voltammetry. Efficient light‐emitting diodes were successfully fabricated. The synthesis, characterization, and electroluminescent properties of the polymers are reported in this study. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 3316–3321, 2002 相似文献