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1.
High conductivity, good stability, and high transmittance in the visible region are the three essential requirements for the polymer electrodes used in the optoelectronic devices. It was found that with addition of diols, such as ethylene glycol, diethylene glycol, or poly(ethylene glycol) (PEG), to the poly(3,4-ethylenedioxythiophene)/poly(styrene sulfonate) (PEDOT:PSS) emulsion before spin-coating could increase dramatically the conductivities of the resultant PEDOT:PSS thin films from 1 to 90 S cm?1 while maintain the optical transparency of the modified thin films. With up to ?2.4 V potential applied, the PEDOT:PSS with PEG 200 additive does not show obvious color change, indicating its good electrochemical stability as polymer electrode. Detailed studies on the structures and morphologies of these modified PEDOT:PSS thin films, in comparison to that of PEDOT:PSS without additives were carried out using AFM, Raman, and FTIR to investigate the underlying mechanisms.  相似文献   

2.
Hybrid films of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) were prepared with different molecular weights of poly(ethylene oxide) (PEO). The cross-linking reaction between PEO and PEDOT:PSS was performed at high temperature and confirmed by using differential scanning calorimeter (DSC), contact angle measurement, and solid-state 1H NMR. The effect of chemical reaction on the conductivity and morphology of these hybrid films was studied by using 4-point probe and atomic force microscope (AFM), respectively. As-spun PEO/PEDOT:PSS films have lower electric conductivity due to the addition of nonconductive PEO, and exhibits no molecular weight dependence on conductivity. After chemical cross-linking reaction at high temperature, only PEDOT:PSS films with lowest molecular weight PEO additives show enhanced conductivity with increasing reaction time. AFM result indicates that the heat-treated PEO/PEDOT:PSS hybrid films show grain-like morphology compared to ethylene glycol treated PEDOT:PSS films which shows continuous PEDOT domain. In the present work we demonstrate that the cross-linking reaction can be used to improve the wet stability of PEDOT:PSS nanofiber, showing good water resistance and excellent dimensional stability.  相似文献   

3.
Poly(3,4-ethylene dioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) counter electrodes, doped with polyethylene glycol (PEG) and acetylene black as binding and conductivity promoting agent, were prepared by a simple mixing method for dye-sensitized solar cell. The electrochemical properties of the electrodes were characterized by cyclic voltammetry, electrochemical impedance spectroscopy (EIS), and Tafel polarization curves. Using PEG dopant, the electrocatalytic activity of PEDOT:PSS electrode was much improved, and further improved by adding a small amount of conducting acetylene black (0.2 wt%). The DSSC cells, using the PEDOT:PSS electrode with PEG (5 wt%) dopant and the composite electrode with PEG (5 wt%)/acetylene black, exhibited an energy conversion efficiency of 3.57 and 4.39 %, comparable with 4.50 % of the commonly used Pt electrode under the same experimental conditions. These results demonstrate that PEG-modified PEDOT:PSS counter electrode is promising to replace the expensive Pt for low cost DSSC, especially to meet the large-scale fabrication demands.  相似文献   

4.
Jianyong Ouyang  Qianfei Xu  Yang Yang  Gang Li 《Polymer》2004,45(25):8443-8450
The conductivity of a poly(3,4-ethylene dioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) film is enhanced by more than 100-folds on adding some organic compounds into PEDOT:PSS aqueous solutions or by treating the PEDOT:PSS film with organic solvents, such as ethylene glycol (EG), 2-nitroethanol, methyl sulfoxide or 1-methyl-2-pyrrolidinone. The mechanism for this conductivity enhancement was studied through various chemical and physical characterizations. The PEDOT:PSS film which is soluble in water becomes insoluble after treatment with EG. This strongly suggests an increased interchain interaction among the PEDOT chains. Raman spectroscopy indicates that this increased interchain interaction results from conformational changes of the PEDOT chains, which change from a coil to linear or expanded-coil structure. The increased interchain interaction and conformation changes are further confirmed by the temperature dependence of conductivity and the electron spin resonance (ESR). It is found that EG treatment lowers the energy barrier for charge hopping among the PEDOT chains, lowers the polaron concentration in the PEDOT:PSS film by ∼50%, and increases the electrochemical activity of the PEDOT:PSS film in NaCl aqueous solution by ∼100%. Atomic force microscopy (AFM) and contact angle measurements show that the surface morphology of the PEDOT:PSS film changes as well after the EG treatment. Conductivity enhancement was also observed when other organic compounds were used, but it was strongly dependent on the chemical structure of the organic compounds, and observed only with organic compound with two or more polar groups. These experimental results support our proposal that the conductivity enhancement is due to the conformational change of the PEDOT chains and the driving force is the interaction between the dipoles of the organic compound and dipoles or charges on the PEDOT chains.  相似文献   

5.
The poly(3,4‐ethylenedioxythiophene) (PEDOT) family of polymers is a technologically important class of conducting polymers showing high stability, medium band gap, low redox potential and high optical transparency in the electrically conductive state. While PEDOT nanotubes and nanofibres have been synthesized electrochemically, significant opportunity exists for developing a convenient chemical synthetic route for the bulk synthesis of nanostructured PEDOT for potential use in the design of next‐generation nano‐electronic circuits and field emission devices. In this paper, chemical oxidative polymerization was used to synthesize PEDOT nanoparticles. These nanoparticles were co‐electrospun with poly(l ‐lactic acid) from a solution in acetone and N,N‐dimethylformamide. The PEDOT particles were analysed using attenuated total reflectance–Fourier transform infrared spectroscopy and particle size distribution using dynamic light scattering. The synthesized nanofibre mats were studied using differential scanning calorimetry and scanning electron microscopy, and conductivity was measured using a two‐probe conductivity tester. © 2016 Society of Chemical Industry  相似文献   

6.
The importance of transparent conductive film is increasing due to its use in applications such as touch‐panel devices. Although indium tin oxide is widely used because of its high conductivity and transparency, conductive polymers are being studied as alternative materials that avoid the use of rare metals and the brittleness associated with existing systems. Polyethylene dioxythiophene (PEDOT)/polyethylene sulfonic acid (PSS) is drawing a lot of attention due to its well‐balanced conductivity, transparency, film formability, and chemical stability. The nonconductive PSS reportedly covers the conductive PEDOT. The PSS shell provides carrier and film‐formability to PEDOT but is also a barrier that hinders electrical conductivity. Therefore, the PEDOT film formability is explored supported by a substrate without the addition of PSS. The “hierarchical nanoporous layer glass” holds the PSS‐free PEDOT with its nanopores to form a homogeneous, transparent film. The PSS‐free PEDOT film thus achieves transparency of over 85% and resistivity of below 500 Ω sq?1.  相似文献   

7.
Electroconductive papers were produced by coating commercial base papers with blends of poly(3,4‐ethylenedioxythiophene)/poly(4‐styrenesulfonate) (PEDOT:PSS) and organic solvents. The bulk conductivities of the coated papers were measured using a four‐probe technique. One‐sided and two‐sided coating gave comparable conductivity levels. The presence of sorbitol and isopropanol in the PEDOT:PSS blends did not enhance the bulk conductivity of the coated paper, and with increasing concentrations of these solvents, the conductivity decreased due to dilution of the conducting component. Samples coated with PEDOT:PSS blends containing N‐methylpyrrolidone (NMP) or dimethyl sulfoxide (DMSO) exhibited a higher conductivity than those coated with pure PEDOT:PSS because of their plasticizing effect and conformational changes of PEDOT molecules indicated by the red shift and disappearance of the shoulder peak at about 1442 cm?1 in the Raman spectra of the coated samples. EDS imaging showed that PEDOT:PSS is distributed throughout the thickness direction of the paper. Contact angle measurements were made to monitor the hydrophilicity of the paper surface and total sulfur analysis was used to determine the amount of PEDOT:PSS deposited onto the paper. The tensile strength of all the paper samples increased slightly after treatment. Thus, it is demonstrated that enhanced bulk conductivity in the order of 10?3 S/cm can be achieved by using organic conductive materials and surface treatment techniques. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010  相似文献   

8.
唐宝坤  李坚  任强  汪称意 《化工学报》2018,69(5):2309-2317
通过RAFT聚合,制备了低分子量的聚乙烯基苯磺酸钠(PSS);其次以低分子量的聚乙烯基苯磺酸钠为模板制备了聚3,4-二氧乙烯噻吩(PEDOT):聚乙烯基苯磺酸钠(PSS)水分散体,研究了作为模板的聚乙烯基苯磺酸钠的不同分子量对PEDOT:PSS水分散体结构和性能的影响。结果显示:通过核磁氢谱(1H NMR)表征,证明成功制备了分子量为3900,4900,9600和18300的聚乙烯基苯磺酸钠。用荧光探针法发现低分子量PSS在水中能形成胶束,临界胶束浓度在10-6g·ml-1左右。用四探针表面电阻测试发现,低分子量PSS为模板可明显提高PEDOT薄膜的导电性,最大提高了近3倍。用紫外可见分光光度计(UV)研究发现,以低分子量PSS为模板使PEDOT的透明性有一定的下降,这主要是由于RAFT试剂部分和PEDOT:PSS的相分离造成的。热稳定性的测试表明,低分子量PSS为模板对PEDOT的热稳定性没有明显的影响。  相似文献   

9.
The goal of this study is to determine the electrically conductivity of the polymers poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate): N-methyl-2-pyrrolidinone (PEDOT: PSS: NMP) and PEDOT: PSS when blended with polyvinyl alcohol (PVA). While the conducting polymers have high conductivity when not blended with PVA, they are brittle and difficult to spin-coat. Thus, the motivation for this study is to develop blends of these two conducting polymers with PVA to produce a material with optimized mechanical properties and that can also be spin-coated. The blends are produced using aqueous preparations of these materials. Mixtures of various weight percentages (wt %) of PEDOT: PSS: NMP and PEDOT: PSS are prepared and spin-coated on glass slides to form thin films. In the blends, the film conductivity increases with increasing content of either PEDOT: PSS: NMP or PEDOT: PSS. For example, 100 wt % of PEDOT: PSS: NMP and 60 wt % of PEDOT: PSS: NMP blended with PVA exhibit conductivities of, respectively, 10 and 4.02 S/cm. In contrast, conductivities of only 0.0525 and 0.000506 S/cm are observed, respectively, for 100 wt % of PEDOT: PSS and 60 wt % of PEDOT: PSS content in the PEDOT: PSS/PVA blends (No NMP). The addition of the NMP enhances the electrical conductivity by two to five orders of magnitude (depending on the amount of PVA in the blend) due to conformational change of PEDOT chains. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012  相似文献   

10.
Here, insignificant conductivity enhancement of PEDOT:PSS through adding different amounts of 2-methylimidazolium ionic liquids into PEDOT:PSS aqueous solutions is reported. Maximum conductivity was reached through 2-methylimidazolium hydrogen sulfate (5 wt.%) addition. It seems that observed conductivity enhancement mainly results from the impact of ionic liquids on the electrical properties and conformational change of PEDOT chains, and through weakening of the electrostatic interactions between PEDOT and PSS. Also, better conductivity was achieved through weak interactions between PEDOT and the PSS chain, which changes the PEDOT conformation and further delocalizes the polarons, as well as changes the electron transport properties.  相似文献   

11.
In this study, the effect of solvents on the morphology and conductivity of poly(3,4‐ethylenedioxythiophene):poly(styrenesulfonate)(PEDOT:PSS) nanofibers is investigated. Conductive PEDOT:PSS nanofibers are electrospun by dissolving a fiber‐forming polymer, polyvinyl alcohol, in an aqueous dispersion of PEDOT:PSS. The conductivity of PEDOT:PSS nanofibers is enhanced 15‐fold by addition of DMSO and almost 30‐fold by addition of ethylene glycol to the spinning dopes. This improvement is attributed to the change in the conformation of the PEDOT chains from the coiled benzoid to the extended coil quinoid structure as confirmed by Raman spectroscopy, X‐ray diffraction, and differential scanning calorimetry. Scanning electron microscopy images show that less beady and more uniform fiber morphology could be obtained by incorporation of ethylene glycol in the spinning dopes. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40305.  相似文献   

12.
Interaction of emeraldine base of polyaniline (PANI) and poly(ethylene-3,4-dioxythiophene): poly(styrenesulfonic acid) (PEDOT:PSS) in a complex solution is shown to lead to a new polymer complex whose components act to each other to favor an increase in intramolecular conductivity in both PANI and PEDOT backbones. Asymmetric changes in intramolecular conductivity of the polymer mixture have been demonstrated upon addition of PANI to PEDOT:PSS dispersion and vise versa. Complex films cast from the solution revealed a specific spherulite-like morphology and increased conductivity up to one order of magnitude as compared to films of the net PEDOT:PSS, which allowed us to conclude on formation of a qualitatively new system rather than a simple blend of the polymers and the effect of cooperative doping of the components by each other, respectively. The doping efficiency was shown to be strongly dependent on the solvent environment and concentration of the polymers in solutions. It is discussed that the increase in conductivity of the composite system is controlled not only by the direct doping of PANI with PSS, but also by weakening of interaction of PSS with the PEDOT backbone itself as a result of the above doping process.  相似文献   

13.
Poly(3,4‐ethylenedioxythiophene) doped with poly(styrenesulfonate) (PEDOT–PSS) was blended with poly(vinyl alcohol) (PVA) to form 0, 10, 20, 30, 40, and 50 vol % PEDOT–PSS/PVA solutions, and their freestanding films were prepared with a simple and cost‐effective solution casting technique at 27 °C in the absence of additives. Field emission scanning electron microscopy images revealed changes in the cocontinuous network to a rodlike morphology in the composite films from 10 to 50 vol % PEDOT–PSS/PVA. The alternating‐current conductivity was found to obey Jonscher's power law. The obtained values of the dielectric constant at 27 °C were relatively high, and a maximum value of 6.7 × 104 at 100 Hz for 40 vol % PEDOT–PSS'/PVA was observed. The dielectric loss attained a maximum value of about 106 at 100 Hz for 40 vol % PEDOT–PSS/PVA. However, a decrease in the dielectric parameters was observed at 50 vol % PEDOT–PSS/PVA because of locally induced strain in the microstructure. The variations in polarization with respect to the applied electric field (P–E) were determined for 50, 100, and 500 Hz at 500 V for the freestanding composite films of lower concentrations up to 20 vol % PEDOT–PSS/PVA. In summary, the dielectric and P–E measurements confirmed that the electrical characteristics changed in accordance to the contribution from both resistive and capacitive sites in the PEDOT–PSS/PVA composites. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45079.  相似文献   

14.
Henry J. Snaith 《Polymer》2005,46(8):2573-2578
We present a microscopic and electronic investigation of the polymeric anode poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) used as an electrode in photovoltaic and single carrier diodes. PEDOT:PSS is processed from aqueous solution as a colloidal dispersion with excess PSS present. We modify the PEDOT:PSS solution by the addition of a high boiling point alcohol, glycerol, which is known to increase the conductivity of the spin-coated film. Atomic force microscopy indicates swelling and greater aggregation of the PEDOT-rich colloidal particles found in this system. Current-voltage characteristics of ‘hole-transporting’ diodes, formed with gold contacts, suggest less surface enrichment of PSS in the glycerol modified electrode. Through Kelvin probe microscopy, we find the surface potential of glycerol modified PEDOT:PSS decreases by approximately 0.12 eV, which we assign to a reduction in surface enrichment by PSS. Photovoltaic diodes, using a PFB:F8BT polymer blend as the photo-active layer, and glycerol modified PEDOT:PSS anodes are significantly improved as compared to those with unmodified PEDOT:PSS anodes. This is likely to be due to improved hole-injection from the active polymer film into the PEDOT:PSS anode. This emphasises the electronic consequences of the morphological reorientation of the PEDOT and PSS.  相似文献   

15.
This paper reports a range of effective sequential chemical processes to enhance the thermoelectric performance of conducting poly(3,4‐ethylenedioxythiophene) films doped with poly(styrene sulfonate) anions (PEDOT:PSS). The electrical conductivity of the PEDOT:PSS films was significantly increased from 0.33 to 3748 S cm?1 after a series of sequential treatments with trifluoroacetic acid (TFA) while the Seebeck coefficient and thermal conductivity were slightly reduced from 17.5 ± 1.2 to 16.0 ± 1.1 μV K?1 and 0.537 to 0.415 W m–1 K?1 for the pristine film and treated film, respectively, leading to a significant improvement in power factor up to 97.1 ± 5.4 μW m–1 K?2. More importantly, around 80% of the electrical conductivity and Seebeck coefficient was retained after 20 days for these TFA‐treated PEDOT:PSS films, revealing the potential for real thermoelectric applications. © 2019 Society of Chemical Industry  相似文献   

16.
Poly(3,4‐ethylene dioxythiophene) (PEDOT) and graphite oxide (GO)/PEDOT composites (GPTs) doped with poly(sodium styrene sulfate) (PSS) were synthesized by in situ polymerization in aqueous media. The electrochemical capacitance performances of GO, PEDOT–PSS, and GPTs as electrode materials were investigated. The GPTs had a higher specific capacitance of 108 F/g than either composite constituent (11 F/g for GO and 87 F/g for PEDOT–PSS); this was attributable to its high electrical conductivity and the layer‐within/on‐layer composite structure. Such an increase demonstrated that the synergistic combination of GO and PEDOT–PSS had advantages over the sum of the individual components. On the basis of cycle‐life tests, the capacitance retention of about 78% for the GPTs compared with that of 66% for PEDOT–PSS after 1200 cycles suggested a high cycle stability of the GPTs and its potential as an electrode material for supercapacitor applications. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011  相似文献   

17.
本研究将金纳米颗粒掺入聚3, 4-乙烯二氧噻吩:聚苯乙烯磺酸(PEDOT:PSS)薄膜中,制备了有机-硅杂化光伏电池。与纯PEDOT:PSS-硅电池相比,掺入金纳米颗粒制备的杂化光伏电池的光电转化效率(PCE)提高了23%,达到12.85%。电池的电流密度-电压曲线(J-V)、外量子效率(EQE)和电容-电压曲线(C-V)测试结果表明,掺入金纳米颗粒后电池性能提高的主要原因在于电池的光学性能和电学性能得到了改善:在金纳米颗粒的等离子共振区域,电池对光的反射性能降低;金纳米颗粒还能提高PEDOT:PSS薄膜的导电率、增加该电池的内建电场,因此极大减少了电荷在传输过程中的损失,提高了电池中电荷的传输和收集效率。  相似文献   

18.
Poly(3,4‐ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) film was prepared from an aqueous dispersion of the polymer treated with 5 wt% dimethylsulfoxide (DMSO) on a glass substrate and was electronically characterized in order to study its electronic properties. The electrical resistance of the polymer film was measured over the temperature range (380–10 K) using four‐point probe technique. It was noticed that the electrical resistance followed three different trends each of which was indicative of a different charge carrier transport mechanism. Each mechanism was investigated in more detail. A semiconductor to metal transition was also observed at 292 K above which dR/dT had a positive slope. Furthermore, Hall effect, electrical conductivity and sheet resistance measurements were performed on the polymer film using van der Pauw technique. The metallic behavior of PEDOT:PSS at room temperature was further evidenced by the results of these measurements. Next, stretchable knitted fabric was coated with PEDOT:PSS prepared from the polymer dispersion treated with 5 wt% DMSO. The conductive fabric was then stretched axially to different amounts of strain and was electrically characterized in both relaxed and stretched states. Despite the constant decrease in its electrical conductivity, the fabric remained electrically conductive while being stretched under increasing applied strain. POLYM. ENG. SCI., 59:1051–1056, 2019. © 2019 Society of Plastics Engineers  相似文献   

19.
Flexible, transparent and conductive polymer blend coatings were prepared from aqueous dispersions of poly(3,4-ethylenedixoythiophene)/poly(styrenesulfonate) [PEDOT/PSS] gel particles (∼80 nm) and latex (∼300 nm). The stable dispersions were deposited as wet coatings onto poly(ethylene terephthalate) substrates and dried at 80 °C. Microstructure studies using tapping mode atomic force microscopy (TMAFM) indicate that a network-like microstructure formed during drying at 0.03 volume fraction PEDOT/PSS loading. In this network-like structure, the PEDOT/PSS phase was forced into the boundary regions between latex. In addition, migration of the PEDOT/PSS particles towards coating surface is likely during drying of the aqueous dispersions. The addition of a small amount of dimethyl sulfoxide (DMSO) in dispersions altered the distribution of the PEDOT/PSS phase. As PEDOT/PSS concentration increases to 0.15 volume fraction, the coating surface is dominated by the PEDOT/PSS phase. The effect of DMSO on microstructure becomes less apparent as PEDOT/PSS concentration increases. The conductivity of the polymer blend coatings increases in a percolation-like fashion with a threshold of ∼0.02 volume fraction PEDOT/PSS. The addition of DMSO in dispersions enhanced the coating conductivity beyond the threshold by more than two orders of magnitude. The highest conductivity, ∼3 S/cm, occurs at 0.20 volume fraction PEDOT/PSS concentration. The polymer blend coatings have good transparency with only a weak dependence of transparency on wavelength due to the small refractive index difference between filler and matrix.  相似文献   

20.
This study describes the preparation of blends between an amorphous polymer (PVC) and a crystalline polymer (PEO), with a third polymeric part that presents electronic conduction capacity (PEDOT‐PSS). Binary (PEO/PVC, PEO/PEDOT‐PSS, PVC/PEDOT‐PSS) and ternary (PVC/PEO/PEDOT‐PSS) blends were prepared by changing the concentrations of the constituents and were analyzed by electronic conductivity, Raman spatial resolution, infrared spectroscopies, and thermogravimetric analysis. The Raman and FTIR analyses showed the incorporation of PEDOT‐PSS within the blends. The higher conductivity presented by the ternary blend was 8.6 × 10?6 Scm?1, composed of 24% of PVC, 16% of PEO, and 60% of PEDOT‐PSS. For binary blends the conductivity was proportional to the PEDOT‐PSS content. The thermal stability could be observed through the TG curves of the blends that presented an increase of 19 K in the weight loss temperature at the 10% level when compared to the pure components. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 1710–1715, 2005  相似文献   

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