PSS Composite Films Research Articles

Hexagonal and Square Patterned Silver Nanowires/PEDOT:PSS Composite Grids by Screen Printing for Uniformly Transparent Heaters.

Transparent conductive films with hexagonal and square patterns were fabricated on poly(ethylene terephthalate) (PET) substrates by screen printing technology utilizing a poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT:PSS) and silver nanowire (Ag NWs) composite ink. The printing parameters—mesh number, printing layer, mass ratio of PEDOT:PSS to Ag NWs and pattern shape—have a significant influence on the photoelectric properties of the composite films. The screen mesh with a mesh number of 200 possesses a suitable mesh size of 74 µm for printing clear and integrated grids with high transparency. With an increase in the printing layer and a decrease in the mass ratio of PEDOT:PSS to Ag NWs, the transmittance and resistance of the printed grids both decreased. When the printing layer is 1, the transmittance and resistance are 85.6% and 2.23 kΩ for the hexagonal grid and 77.3% and 8.78 kΩ for the square grid, indicating that the more compact arrangement of square grids reduces the transmittance, and the greater number of connections of the square grid increases the resistance. Therefore, it is believed that improved photoelectric properties of transparent electrodes could be obtained by designing a printing pattern with optimized printing parameters. Additionally, the Ag NWs/PEDOT:PSS composite films with hexagonal and square patterns exhibit high transparency and good uniformity, suggesting promising applications in large-area and uniform heaters.

Proton‐Irradiation Effects on the Thermoelectric Properties of Flexible Bi2Te3/PEDOT:PSS Composite Films

AbstractBismuth telluride (Bi2Te3) and poly(3,4‐ethylenedioxythiophene) doped with poly(styrene sulfonate) (PEDOT:PSS) are two major inorganic and organic thermoelectric (TE) materials that are widely investigated for TE device applications. An inorganic–organic composite, based on Bi2Te3 and PEDOT:PSS possessing a high TE figure of merit, has immense potential in fabricating highly efficient and flexible TE generators. In order to achieve an enhanced TE performance, the interdependent TE parameters such as electrical conductivity and Seebeck coefficient of the composite should be decoupled. In this study, the TE properties of the composites are enhanced through the creation of additional defects in Bi2Te3 via proton irradiation. The structural variations occurred in Bi2Te3 via proton irradiation are analyzed using X‐ray diffraction, X‐ray photoelectron spectroscopy, and transmission electron microscopy, which quantitatively reveal structural damages as well as deviations from the Bi2Te3 stoichiometry. The proton irradiation‐induced antisite defects in the Bi2Te3 crystal are found to be beneficial in decoupling the interdependent TE parameters of Bi2Te3/PEDOT:PSS composite thin films, through which enhanced TE performance is achieved. The findings demonstrate that proton irradiation of Bi2Te3 is an effective method to engineer the TE properties through inducing defects in Bi2Te3 and enhancing the interaction between Bi2Te3 and PEDOT:PSS.

Poly(3,4‐ethylenedioxythiophene) Polymer Composite Bioelectrodes with Designed Chemical and Topographical Cues to Manipulate the Behavior of PC12 Neuronal Cells

AbstractControlled extracellular chemical and topographical cues can generate physicochemical changes that influence the proliferation and differentiation of neural cells; external electrical stimulation (ES) via conductive bioelectrodes can promote neural differentiation by increasing neurite outgrowth. Rat pheochromocytoma (PC12) cells are used as a neuron‐like model cells to explore the possibility of using a well‐designed poly(ethylene oxide) (PEO)/poly(3,4‐ethylenedioxythiophene):polystyrenesulfonate (PEDOT:PSS) blend solution to fabricate functional bioelectrodes presenting biological fouling/antifouling surfaces, thereby regulating the cell adhesion, proliferation, and differentiation properties. In this study, it is found that a flat PEO/PEDOT:PSS composite film fabricates through spin‐coating, operates through a contact repulsion mechanism that limits cell attachment and proliferation; in contrast, the aligned and random PEO/PEDOT:PSS nanofibers fabricates through electrospinning promoted neuron adhesion efficiently and allows manipulation of the cell morphology. Furthermore, ES of PC12 cells is performed to investigate the influence of the conductive random and aligned PEO/PEDOT:PSS composite nanofiber mats on the enhancement of neurite outgrowth, as well as the relative gene expression of Nestin, Tuj1, and MAP2. Therefore, combining this unique PEDOT:PSS blend solution with various fabrication processes appears to be a facile approach toward bioelectronic interface coatings displaying tunable surface properties for manipulating the cellular behavior of neurons during ES.

Ultrathin Biomimetic Polymeric Ti3C2T x MXene Composite Films for Electromagnetic Interference Shielding.

Lightweight, ultrathin, and flexible electromagnetic interference (EMI) shielding materials with high electromagnetic shielding effectiveness (SE) and excellent mechanical robustness are greatly desired for miniaturized and highly integrated electronics. Herein, for the first time, a freestanding, ultrathin, and flexible Ti3C2T x/poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) composite film with a "brick-and-mortar" structure is biomimetically designed and fabricated via a vacuum-assisted filtration process. The ultrathin polymeric composite film with a weight ratio 7:1 of Ti3C2T x to PEDOT:PSS is only 11.1 μm in thickness but exhibits a high EMI SE value of 42.10 dB. Meanwhile, the tensile strength increases considerably from 5.62 to 13.71 MPa and the corresponding ruptured strain increases from 0.18 to 0.29% compared with pure Ti3C2T x MXene film, respectively. Moreover, the hybrid film displays a superior conductivity of 340.5 S/cm and an outstanding specific EMI shielding efficiency of 19 497.8 dB cm2 g-1. The superior electrical conductivity and specific EMI shielding efficiency imply the excellent potential of the Ti3C2T x/PEDOT:PSS composite films for ultrathin, lightweight, and flexible EMI shielding materials.

Preparation and thermoelectric properties of PEDOT:PSS coated Te nanorod/PEDOT:PSS composite films

Abstract PEDOT:PSS coated Te (PC Te) nanorod/PEDOT:PSS composite films were prepared by a drop-casting technique. H2SO4 treatment was employed to enhance thermoelectric (TE) properties of the composite films. The addition of PC Te nanorods increased both the electrical conductivity and the Seebeck coefficient of the composite films. An optimized power factor of 141.9 μW/mK2 was obtained for the film containing 90 wt% PC Te nanorods treated with 12 M H2SO4 at room temperature, which was 2.75 times as high as that of the untreated composite film, corresponding to the electrical conductivity and Seebeck coefficient of 204.6 S/cm and 83.27 μV/K, respectively. XPS and GIWAXS analysis revealed the removal of insulating PSS units and the rearrangement of PEDOT chains after the H2SO4 treatment. Finally, a 9-leg TE generator prototype was fabricated using the optimized composite film. The maximum output power and area output power density produced from the prototype were 47.7 nW and 57.2 μW/cm2, respectively, at the temperature difference of 40 K.

Surface plasmon spectroscopy of thin composite films of Au nanoparticles and PEDOT:PSS conjugated polymer

Abstract We studied the effect of Au nanoparticles (NPs) on optical properties of composite films of poly(3,4-ethylenedioxythiophene): poly (styrenesulfonate) (PEDOT:PSS) mixed with Au NPs of 20, 40 and 60 nm in diameter by surface plasmon resonance (SPR) spectroscopy. The excitation wavelength of SPR redshifts with increasing the concentration of Au NPs in the Au/PEDOT:PSS composite films. The SPR spectra were simulated by using transfer matrix method (TMM) and effective medium approximation (EMA). The SPR wavelength redshift was ascribed to the film thickness increase of Au/PEDOT:PSS composites rather than effective permittivity variation of the composite films induced with Au NPs inclusion.

Nanotube and poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) composite film for the electrode applications in organic thin-film transistor and dye-sensitized solar cells

In this study, composite films made of coiled carbon nanotubes (CCNTs) and poly(3,4-ethylenedioxythiophene) polymerized with poly(4-styrenesulfonate) (PEDOT:PSS) were fabricated with different composition ratios. The variations in film properties (including surface morphology, work function, and electrical conductivity) in accordance with the amount of CCNT dosing were investigated. Subsequently, through HCl-methanol treatment, we achieved a significant enhancement in electrical conductivity with little damage to the CCNT features. The characteristics of CCNT/PEDOT:PSS composite film are generally comparable to those of PEDOT:PSS film, and some of them, such as catalytic activity and work function, are significantly higher. On the basis of these versatile features, the CCNT/PEDOT:PSS composite films exhibit excellent performance as source/drain electrode in organic thin-film transistors and as catalytic counter electrode in dye-sensitized solar cells.

Layer-by-layer assembly of iron oxide-decorated few-layer graphene/PANI:PSS composite films for high performance supercapacitors operating in neutral aqueous electrolytes

The layer-by-layer assembly of polyaniline-PSS (PANI:PSS) complexes and iron oxide nanoparticles-decorated few-layer graphene (Fe-FLG) from aqueous dispersions, yielding an electrode material with excellent electrochemical capacitive performance in simple neutral aqueous electrolyte is presented. The simple dip-coating procedure allows the effective incorporation of both materials and the control of the film nanoarchitectonics. The resulting composite coating was characterized by XPS and Raman spectroscopies. A linear dependence of the capacitance on the film mass indicates that both building blocks are efficiently (and electrochemically) connected within the films. The electrochemical performance of the film-coated electrodes was tested in both acidic (0.1 M HCl) and neutral (0.1 M KCl) aqueous electrolytes. Electrodes constituted of 15 self-assembled bilayers showed the best performance with a high capacitance of 768.6 F g−1 and 659.2 F g−1 in 0.1 M HCl and 0.1 M KCl, respectively, at the current density of 1 A g−1. Moreover, a high stability to continuous cycling was observed, even in aqueous neutral solution (86% capacitance retention after 1600 cycles at 3 A g−1). This ternary material then constitutes a promising candidate for the construction of environmentally friendly supercapacitors.

Electrochemical redox induced rapid uptake/release of Pb(II) ions with high selectivity using a novel porous electroactive HZSM-5@PANI/PSS composite film

A porous electroactive composite based film made of core@shell nanospheres is uniformly fabricated on the conductive substrate by artfully applying the alternative assembly of the polyaniline/polystyrene (PANI/PSS) and the high-crystalline protonated Zeolite Socony Mobil-5 (HZSM-5) nanospheres via a potential pulse method. The isolated HZSM-5 nanospheres are interconnected and linked up by the chains of PANI/PSS that act as bridges for electron transportation. In this composite film, the HZSM-5 nanospheres provide the protons to further improve the electroactivity of PANI based on the unique proton “round-trip” transfer effect during the electrochemical redox process. The obtained HZSM-5@PANI/PSS composite based film shows fast electrochemical uptake/release ability for the removal of Pb2+ ions from the aqueous solution because of the strong driving force resulting from the electric field, and the adsorption equilibrium time is less than 60 min. When the initial concentration of Pb2+ ions is 100 mg L−1, the ion adsorption quantity reaches 240.6 mg g−1 and retains 97.1% of its initial value after 5 uptake/release cycles. Especially, the selectivity factors of the HZSM-5@PANI/PSS film for Pb2+/Ni2+, Pb2+/Co2+, Pb2+/Cd2+, and Pb2+/Zn2+ reach up to 21.97, 26.19, 24.61, and 39.29, respectively. Such high selectivities for Pb2+ ions are realized by artfully using the significantly lower Gibbs energy of dehydration of Pb2+ ions than that of other listed metal ions, which makes the Pb2+ ions easily adsorbed into the composite film based on the confinement effect of the HZSM-5. Furthermore, the consumed energy for dehydration is supplied by the electric field, resulting in the decrease of the ions transport resistance and the increase of the adsorption capacity of the composite film.

Preparation of Sb2S3 nanocrystals modified TiO2 dendritic structure with nanotubes for hybrid solar cell

Array of TiO2 dendritic structure with nanotubes was constructed on transparent conductive fluorine-doped tin oxide glass (FTO) with titanium potassium oxalate as titanium source. Sb2S3 nanocrystals were successfully deposited on the TiO2 substrate via spin-coating method. Furthermore, TiO2/Sb2S3/P3HT/PEDOT:PSS composite film was prepared by successively spin-coating P3HT and PEDOT:PSS on TiO2/Sb2S3. It was demonstrated that the modification of TiO2 dendritic structure with Sb2S3 could enhance the light absorption in the visible region. The champion hybrid solar cell assembled by TiO2/Sb2S3/P3HT/PEDOT:PSS composite film achieved a power conversion efficiency (PCE) of 1.56%.

Efficiency Enhancement of Perovskite Solar Cells via Electrospun CuO Nanowires as Buffer Layers.

CuO nanowires (NWs) with the diameters ranging from 130 to 275 nm have been successfully prepared by electrospinning technique, followed by a calcination process. Inverted planar heterojunction perovskite solar cells (PSCs) with the structure of indium tin oxide/CuO NWs/poly(3,4-ethylenedioxythiophene) (PEDOT):poly(styrenesulphonate) (PSS)/CH3NH3PbI3/phenyl C61-butyric acid methyl ester/Bphen/Ag were designed, achieving a best power conversion efficiency (PCE) of 16.87%, which is 21% improvement compared to that of the control PSCs without CuO NWs. By the characterizations of an optical microscope, X-ray diffraction, and scanning electron microscopy, it was found that CuO NWs have uniform morphology and orderly arrangement. Electrochemical impedance spectrometry and external quantum efficiency were used to reveal the effect of CuO NWs on the performance of PSCs. Compared to ZnO NWs with the same diameters and quantitative analysis based on a simple model, we conclude that the improvement of PCE by about 13% can be ascribed to the increase of the PEDOT:PSS/CH3NH3PbI3 interface area and the remaining increase of 8% can be attributed to the higher hole mobility of the CuO NWs/PEDOT:PSS composite film. The results indicate that the efficiency of PSCs will have a significant enhancement when the optimal CuO NWs are introduced into the charge transport layer.

Solution processed metal-doped NiS/PEDOT:PSS composite thin films as an efficient electrode for quantum-dot sensitized solar cells

Cu-doped NiS with PEDOT:PSS chrysanthemum flower-like structures, which were composed of many nanopetal bunches in a radial fashion, were synthesized using a modest, eco-friendly and cost effective method. The 5 wt.% Cuph/PEDOT:PSS produced a minute amount of PEDOT:PSS, which exhibiting outstanding electrochemical performance in QDSSCs. The synergetic effects of the composite were investigated and a PCE of 4.87%, fill factor of 0.51, Jsc of 13.75 mA cm−2, and Voc of 0.549 V in a polysulfide electrolyte were obtained. The electrode exhibited great electrocatalytic activities and lower charge transfer resistance than that of the bare NiS and Cu-doped NiS, making it a promising material for both fuel cells and QDSSCs. The improved performance of the 5 wt.% Cuph/PEDOT:PSS electrode was attributed mainly to the large surface area, greater electrical conductivity and high electrocatalytic activity.

Effect of silver decorated graphene oxide on the PEDOT:PSS-matrix composite films

Silver decorated graphene oxide (GO) was added in poly(3,4-ethylenedioxythiopphene): poly(styrene sulfonate) (PEDOT:PSS) matrix to fabricate composite films, aiming for an improved electrical conductivity. Silver particles were deposited on GO surfaces by reaction with Tollens’ reagent. The composite films reinforced by silver decorated GO showed a sheet resistance of 744 Ω/sq. with 88.9% transparency, which outperformed PEDOT:PSS matrix and GO/PEDOT:PSS composite films. The deposited silver particles were consisted of elementary silver and positively charged silver. The GO surfaces were negatively charged. The distinction of positive domain and negative domain on silver decorated GO surfaces promoted the phase separation of conductive PEDOT molecules and insulting PSS molecules, which contributed to the increase of the electrical conductivity of the composite films. Moreover, the deposition of elementary silver introduced extra electron pathways in the composite films.

High‐Performance Ultrathin Flexible Solid‐State Supercapacitors Based on Solution Processable Mo1.33C MXene and PEDOT:PSS

AbstractMXenes, a young family of 2D transition metal carbides/nitrides, show great potential in electrochemical energy storage applications. Herein, a high performance ultrathin flexible solid‐state supercapacitor is demonstrated based on a Mo1.33C MXene with vacancy ordering in an aligned layer structure MXene/poly(3,4‐ethylenedioxythiophene):poly(styrenesulfonic acid) (PEDOT:PSS) composite film posttreated with concentrated H2SO4. The flexible solid‐state supercapacitor delivers a maximum capacitance of 568 F cm−3, an ultrahigh energy density of 33.2 mWh cm−3 and a power density of 19 470 mW cm−3. The Mo1.33C MXene/PEDOT:PSS composite film shows a reduction in resistance upon H2SO4 treatment, a higher capacitance (1310 F cm−3) and improved rate capabilities than both pristine Mo1.33C MXene and the nontreated Mo1.33C/PEDOT:PSS composite films. The enhanced capacitance and stability are attributed to the synergistic effect of increased interlayer spacing between Mo1.33C MXene layers due to insertion of conductive PEDOT, and surface redox processes of the PEDOT and the MXene.

Preparation of 2D MoSe2/PEDOT:PSS composite and its thermoelectric properties

Nowadays, inorganic/polymer composites have attracted significant interest in thermoelectric field, since the composite materials usually achieve their respective advantages complementary to each other. In this work, molybdenum diselenide (MoSe2) was synthesized by a facile hydrothermal method. Solution processible two-dimensional (2D) MoSe2 nanosheets (NSs) were successfully obtained using dimethylsulfoxide (DMSO) solvent or lithium intercalation procedure. Combined with Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS), MoSe2/PEDOT:PSS composite thin films were fabricated by direct vacuum-filtration method. Thermoelectric properties of composite thin films were investigated systematically and found that 2D MoSe2 NSs and PEDOT:PSS have the synergistic effect on improving thermoelectric properties. The maximum power factor was calculated to be 48.6 µW m−1 K−2 with 5 wt% 2D MoSe2 NSs embedding into PEDOT:PSS matrix, which is almost 69% higher than that of pure PEDOT:PSS. These results demonstrate that 2D inorganic/polymer composite method is one of promising strategies to get high-performance polymer-based thermoelectric composites.

Synthesis and characterization of transparent conducting SWCNT/PEDOT: PSS composite films by spin coating technique

Transparent conducting carbon nanotube (CNT)/Poly (3,4 ethylenedioxy thiophene) poly(4-styrenesulfonate) (PEDOT:PSS) composite films are prepared by spin coating technique. The loading rate of CNTs in the host polymer is optimised to enhance the conductivity of the polymer without compromising the transparency of PEDOT:PSS. The effect of single walled CNT (SWCNT) loading on the transparency and conductivity are systematically studied using UV–vis-NIR Spectrophotometry and Hall Measurement. The structural features of the polymer are found to be unaffected by the incorporation of CNTs through XRD, FTIR and Raman analysis. The SWCNT form a network with the PEDOT:PSS matrix which enhances the conductivity of host. A six fold increase in the electrical conductivity of PEDOT:PSS is observed upon incorporation of 0.35wt% of SWCNT when the figure of merit of the transparent conductor is reduced by 102.

Systematic optimization of MWCNT-PEDOT:PSS composite electrodes for organic transistors and dye-sensitized solar cells: Effects of MWCNT diameter and purity

Abstract Multi-walled carbon nanotubes (MWCNTs) and polymer composites have attracted significant attention as metal-free electrode materials for various electronic devices. Many studies have presented strategies to enhance the electrical conductivity of MWCNT/polymer composites. However, systematic studies on the effects of MWCNT features on the composite properties are still missing. Such studies can further the development of MWCNT/polymer-based conducting materials. Herein, we characterize composite films of MWCNTs and poly(3,4-ethylenedioxythiophene) polymerized with poly(4-styrenesulfonate) (PEDOT:PSS), with variations in the MWCNT diameter and purity. MWCNT features greatly affect the physical/chemical/electrical properties of the MWCNT/PEDOT:PSS composite films. In addition, the diameter and purity of MWCNTs also influenced the transition behavior of the composite films during the hydrochloric acid-methanol treatment, which was performed for increasing electrical conductivity. As a result, we could optimize the performance of organic transistors and dye-sensitized solar cells (DSSCs) using MWCNT/PEDOT:PSS composite films as source/drain electrodes and catalytic counter electrodes, respectively. Furthermore, using the optimized device parameters, we successfully fabricated high performance fluorine doped tin oxide-free DSSCs and high-gain organic complementary inverters using MWCNT/PEDOT:PSS composite electrodes.

Layered Tb‐Doped Yttrium Carboxyphosphonate Nanocrystals as Efficient Filler for PEDOT:PSS Composite Films

AbstractA layered yttrium phosphonate based on N‐(phosphonomethyl)glycine (H3L) and of formula Y(PO3CH2NHCH2COOH)(HPO3CH2NHCH2COOH) was synthesized in mild hydrothermal conditions. Its crystal structure was first determined by single‐crystal X‐ray diffraction. Then, the synthetic parameters were changed in order to reduce the particle size of the compound. The use of microwave (MW) irradiation during the synthesis allowed a) to obtain the compound in form of nanoparticles (NP) in the 50–300 nm range dispersed in water, b) to strongly reduce the reaction time by a factor 150, and c) to successfully introduce into the structure small amounts of a luminescent ion like terbium(III) as an isomorphic substituent of yttrium(III). The obtained NP were used to prepare composite materials by dispersing them in poly(3,4‐ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS). The resulting optical, photophysical, morphological and electrical properties of modified and pristine PEDOT:PSS films were investigated and compared, in order to test the potential use of Y(H2L)(HL) NP as luminescent downshifting materials in optoelectronic devices.

Highly enhanced thermoelectric performance of WS2 nanosheets upon embedding PEDOT:PSS

ABSTRACTTwo‐dimensional (2D) WS2 nanosheets (NSs) as a promising thermoelectric (TE) material have gained great concern recently. The low electrical conductivity significantly limits its further development. Herein, we reported an effective method to enhance the TE performance of WS2 NSs by combining poly(3,4‐ethylenedioxythiophene):poly(4‐styrenesulfonate) (PEDOT:PSS). The restacked WS2 NSs thin film with 1T phase structure obtained by a common chemical lithium intercalation show a high Seebeck coefficient of 98 μV K−1 and a poor electrical conductivity of 12.5 S cm−1. The introduction of PEDOT:PSS with different contents obviously improve the electrical conductivity of WS2 NSs thin films. Although a declining Seebeck coefficient was observed, an optimized TE power factor of 45.2 μW m−1 k−1 was achieved for WS2/PEDOT:PSS composite thin film. Moreover, the as‐prepared WS2/PEDOT:PSS thin film can be easily peeled off and transferred to other substrate leading to a more promising application. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2017, 55, 997–1004

Improved functionality of PEDOT:PSS thin films via graphene doping, fabricated by ultrasonic substrate vibration-assisted spray coating

The composite thin film of graphene and PEDOT:PSS (poly(3,4-ethylenedioxythiophene) polystyrene sulfonate) is a promising candidate of hole transport layer and transparent conductive electrode materials for low-cost thin film devices. We use novel, fast, controllable and scalable ultrasonic substrate vibration-assisted spray coating (SVASC) method to fabricate high-performance graphene-PEDOT:PSS composite thin films. Graphene sheets are uniformly dispersed in aqueous PEDOT:PSS solution using sodium dodecyl sulfonate as surfactant. The fabricated graphene-PEDOT:PSS composite thin films exhibit excellent electrical and optical properties. The electrical conductivity of composite PEDOT:PSS thin films reaches 720S/cm, which is increased about 10 times when 0.02wt% of graphene is incorporated in the precursor solution. This remarkable enhancement is ascribed to the higher carrier mobility and carrier concentration, because graphene sheets bridge between the PEDOT:PSS rings via the strong π-π interaction acting as high-mobility channel. Also, the π-π interaction causes a reduction in the defect sites in PEDOT:PSS. Moreover, a mild drying temperature of 80°C is favored, leading to better structural arrangement of graphene bridging between the polymer segments, and higher electrical conductivity. This work simplifies the solution-processing of graphene and uses a scalable casting technique, which paves the way for the commercialization of low-cost flexible electronic devices.