Flexible,stretchable and conductive PVA/PEDOT:PSS composite hydrogels prepared by SIPN strategy

Stretchable conductive hydrogels have received significant attention due to their possibility of being utilized in wearable electronics and healthcare devices. In this work, a semi-interpenetrating polymer network (SIPN) strategy was employed to fabricate a set of flexible, stretchable and conductive composite hydrogels composed of polyvinyl alcohol (PVA) in the presence of glutaraldehyde as the crosslinker, HCl as the catalyst and poly(3,4-ethylenedioxythiophene):polystyrenesulfonate (PEDOT:PSS) as the conductive medium. The results from FTIR, Raman, SEM and TGA indicate that a chemical crosslinking network and interactions of PVA and PEDOT:PSS exist in the SIPN hydrogels. The swelling ratio of hydrogels decreased with increasing content of PEDOT:PSS. Due to the chemical crosslinking network and interactions of PVA and PEDOT:PSS, PVA networks semi-interpenetrated with PEDOT:PSS exhibited excellent tensile and compression properties. The tensile strength and elongation at breakage of the composite hydrogels with 0.14 wt% PEDOT:PSS were 70 KPa and 239%, respectively. The compression stress of the composite hydrogels with 0.14 wt% PEDOT:PSS at a strain of 50% was about 216 KPa. The electrical conductivity of the hydrogels increased with increasing PEDOT:PSS content. The flexible, stretchable and conductive properties endow the composite hydrogel sensor with a superior gauge factor of up to 4.4 (strain: 100%). Coupling the strain sensing capability to the flexibility, good mechanical properties and high electrical conductivity, we consider that the designed PVA/PEDOT:PSS composite hydrogels have promising applications in wearable devices, such as flexible electronic skin and sensitive strain sensors.     

Conductivity enhancement of PEDOT:PSS film via sulfonic acid modification: application as transparent electrode for ITO-free polymer solar cells

3-Hydroxy-1-propanesulfonic acid(HPSA)was applied as a modification layer on poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate)(PEDOT:PSS)film via spin-coating,resulting in a massive boost of the conductivity of PEDOT:PSS film,and thus the as-formed PEDOT:PSS/HPSA bilayer film was successfully used as a transparent electrode for ITO-free polymer solar cells(PSCs).Under the optimized concentration of HPSA(0.2 mol L~(-1)),the PEDOT:PSS/HPSA bilayer film has a conductivity of 1020 S cm~(-1),which is improved by about 1400 times of the pristine PEDOT:PSS film(0.7 S cm~(-1)).The sheet resistance of the PEDOT:PSS/HPSA bilayer film was 98Ωsq~(-1),and its transparency in the visible range was over 80%.Both parameters are comparable to those of ITO,enabling its suitability as the transparent electrode.According to atomic force microscopy(AFM),UV-Vis and Raman spectroscopic measurements,the conductivity enhancement was resulted from the removal of PSS moiety by methanol solvent and HPSA-induced segregation of insulating PSS chains along with the conformation transition of the conductive PEDOT chains within PEDOT:PSS.Upon applying PEDOT:PSS/HPSA bilayer film as the transparent electrode substituting ITO,the ITO-free polymer solar cells(PSCs)based on poly[N-9″-hepta-decanyl-2,7-carbazole-alt-5,5-(4′,7′-di-2-thienyl-2′,1′,3′-benzothiadiazole)]:[6,6]-phenyl C71-butyric acid methyl ester(PC_(71)BM)(PCDTBT:PC_(71)BM)active layer exhibited a power conversion efficiency(PCE)of 5.52%,which is comparable to that of the traditional ITO-based devices.     

Large-area,flexible polymer solar cell based on silver nanowires as transparent electrode by roll-to-roll printing

Conventional organic solar cell’s (OSC) architectures, including rigid transparent substrate (Glass), conductive electrode (Indium tin oxide, ITO) and small working areas, are widely utilized in organic photovoltaic fields. However, such a structure as well as conventional spin-coating method obviously restrict their industrial application. In this article, we report the deposition of silver nanowires (AgNWs) on the flexible substrate by slot-die printing. The obtained AgNWs films exhibited a high transmittance and a low resistance, and were further used as the transparent conductive electrode of OSCs. A typical conjugated polymer, poly[(2,5-bis(2-hexyldecyloxy)phenylene)-alt-(5,6-difluoro-4,7-di(thiophen-2-yl)benzo[c] [1,2,5]thiadiazole)] (PPDT2FBT), was used as the active material to fabricate large-area (7 cm² solar cells by a slot-die coating process. The power conversion efficiency (PCE) could reach 1.87% initially and further increased to 3.04% by thermal annealing. Compared to the performance of reference cell on ITO substrate, the result indicated that the AgNWs could be developed as an alternative substitute of conductive electrode to fabricate the large-area flexible OSCs by roll-to-roll printing.     

基于WOx/PEDOT:PSS复合空穴传输层的高效稳定平面异质结钙钛矿太阳电池

在基于钙钛矿/富勒烯平面异质结的钙钛矿太阳电池中,PEDOT:PSS是最常使用的空穴传输材料. 但PEDOT:PSS呈酸性,会腐蚀金属氧化物透明电极,使器件的电极界面稳定性欠佳. 本文将高功函的氧化钨（WO_x）插入到PEDOT:PSS和FTO之间,形成WO_x/PEDOT:PSS复合空穴传输层,这样既可以避免PEDOT:PSS与FTO直接接触,提高器件的稳定性,又可以进一步降低电极界面的接触势垒,从而提升器件的性能. 作者研究了复合传输层对透光率、钙钛矿形貌、钙钛矿结晶、光伏性能及器件稳定性的影响. 基于WO_x/PEDOT:PSS复合空穴传输层的电池效率可以达到12.96%,比单纯的PEDOT:PSS的电池效率(10.56%)提升了22.7%,同时器件的稳定性也得到大幅改善.     

Photolithographic patterning of highly conductive PEDOT:PSS and its application in organic light‐emitting diodes

Photolithographically patterned highly conductive (～1400 S/cm) poly(3,4‐ethylenedioxythio‐phene):poly(styrenesulfonate) (PEDOT:PSS) films are demonstrated as electrodes for organic light emitting diodes (OLEDs). With the assistance of hydrofluoroether (HFE) solvents and fluorinated photoresists, high‐resolution passive‐matrix OLEDs with PEDOT:PSS electrodes are fabricated, in which the OLEDs show comparable performance to those devices prepared on the indium tin oxide (ITO) electrodes. This photolithographic patterning process for PEDTO:PSS has great potential for applications which require flexible electrodes. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2014 , 52, 1221–1226     

Influence of a water rinse on the structure and properties of poly(3,4-ethylene dioxythiophene):poly(styrene sulfonate) films

Poly(3,4-ethylene dioxythiophene):poly(styrene sulfonic acid) (PEDOT:PSS) films exhibit a complex structure of interconnected conductive PEDOT domains in an insulating PSS matrix that controls their electrical properties. This structure is modified by a water rinse, which removes PSS with negligible PEDOT loss. Upon PSS removal, film thickness is reduced by 35%, conductivity is increased by 50%, and a prominent dielectric relaxation is eliminated. These results suggest that the removed PSS is not associated with PEDOT and that the conductive domain network is not substantially altered by the removal of a significant fraction of insulator. The removal of PSS may benefit organic light emitting diode fabrication by reducing acid attack on indium tin oxide electrodes and lead to more robust performance in switching circuits by extending the working frequency range.     

Stable aqueous dispersion of reduced graphene nanosheets via non-covalent functionalization with conducting polymers and application in transparent electrodes

We developed a simple and facile method of producing a stable aqueous suspension of reduced graphene oxide (RGO) nanosheets through the chemical reduction of graphene oxide in the presence of a conducting polymer dispersant, poly(3,4-ethylene dioxythiophene):poly(styrene sulfonate) (PEDOT:PSS). This approach involves the cooperative interactions of strong π- π interactions between a two-dimensional graphene sheet and a rigid backbone of PEDOT and the intermolecular electrostatic repulsions between negatively charged PSS bound on the RGO sheets, which impart the colloidal stability of the resulting hybrid nanocomposite of RGO/PEDOT. Moreover, our one-step solution-based method allows preserving the intrinsic chemical and electronic properties of both components, yielding a hybrid film of RGO nanosheets of high conductivity of 2.3 kΩ/sq with a transmittance of 80%. By taking advantage of conducting network structure of conducting polymers which provides an additional flexibility and mechanical stability of RGO nanosheets, we demonstrate the potential application of hybrid RGO/PEDOT as highly flexible and transparent electrodes.     

Highly Conductive PEDOT:PSS Films with 1,3‐Dimethyl‐2‐Imidazolidinone as Transparent Electrodes for Organic Light‐Emitting Diodes

Highly conductive poly(3,4‐ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) films as transparent electrodes for organic light‐emitting diodes (OLEDs) are doped with a new solvent 1,3‐dimethyl‐2‐imidazolidinone (DMI) and are optimized using solvent post‐treatment. The DMI doped PEDOT:PSS films show significantly enhanced conductivities up to 812.1 S cm⁻¹. The sheet resistance of the PEDOT:PSS films doped with DMI is further reduced by various solvent post‐treatment. The effect of solvent post‐treatment on DMI doped PEDOT:PSS films is investigated and is shown to reduce insulating PSS in the conductive films. The solvent posttreated PEDOT:PSS films are successfully employed as transparent electrodes in white OLEDs. It is shown that the efficiency of OLEDs with the optimized DMI doped PEDOT:PSS films is higher than that of reference OLEDs doped with a conventional solvent (ethylene glycol). The results present that the optimized PEDOT:PSS films with the new solvent of DMI can be a promising transparent electrode for low‐cost, efficient ITO‐free white OLEDs.

     

Free‐Standing Conducting Polymer Films for High‐Performance Energy Devices

Thick, uniform, easily processed, highly conductive polymer films are desirable as electrodes for solar cells as well as polymer capacitors. Here, a novel scalable strategy is developed to prepare highly conductive thick poly(3,4‐ethylenedioxythiophene):polystyrene sulfonate (HCT‐PEDOT:PSS) films with layered structure that display a conductivity of 1400 S cm^?1 and a low sheet resistance of 0.59 ohm sq^?1. Organic solar cells with laminated HCT‐PEDOT:PSS exhibit a performance comparable to the reference devices with vacuum‐deposited Ag top electrodes. More importantly, the HCT‐PEDOT:PSS film delivers a specific capacitance of 120 F g^?1 at a current density of 0.4 A g^?1. All‐solid‐state flexible symmetric supercapacitors with the HCT‐PEDOT:PSS films display a high volumetric energy density of 6.80 mWh cm^?3 at a power density of 100 mW cm^?3 and 3.15 mWh cm^?3 at a very high power density of 16160 mW cm^?3 that outperforms previous reported solid‐state supercapacitors based on PEDOT materials.     

Electro-catalytic role of insulator/conductor interface in Mg O/PEDOT composite electrodes for dye-sensitized solar cells

Mg O has not been explored as a counter electrode materials for dye-sensitized solar cells(DSSCs)due to its lack of electrical conductivity.However,herein,it is reported that Mg O insulator with conductive poly(3,4-ethylenedioxythiophene):polysty-renesulfonate(PEDOT:PSS)exhibited excellent performance as a counter electrode for DSSCs,leading to a high power conversion efficiency of 7.45%.Furthermore,it was revealed that the interface between Mg O and PEDOT:PSS plays an important electro-catalytic role in the Mg O/PEDOT composite counter electrodes.     

导电高分子的最近进展

因为导电高分子结合了金属与塑料的优点,他们一直受到很大的关注。但是他们的应用受到一些因素的影响,包括他们的电学性质,稳定性和可加工性。近来,导电高分子的性能得到很大的提高。他们在许多领域的重要应用被论证,比如透明电极,可拉伸电极,神经界面,热电转换和能量储存。这篇文章简单综述了导电高分子的电导提高和它们在热电转换,超级电容器和电池的应用。     

An Alternative Anionic Polyelectrolyte for Aqueous PEDOT Dispersions: Toward Printable Transparent Electrodes

Organic conducting polymers are promising electrode materials for printable organic electronics. One of the most studied conducting polymers is PEDOT:PSS, which is sufficiently conductive and transparent, but which shows some drawbacks, such as hygroscopicity and acidity. A new approach to stabilize PEDOT in aqueous dispersions involves the replacement of PSS with a basic polyanion based on a polystyrene backbone with (trifluoromethylsulfonyl)imide (TSFI) side groups. The PEDOT:PSTFSIK dispersions were obtained by oxidative polymerization of EDOT in an aqueous PSTFSIK solution and were characterized with regard to their composition, morphology, doping, rheological behavior, and optoelectronic performance. The PEDOT:PSTFSIK dispersions showed excellent printability and good optoelectronic performance (238 Ohm sq^?1 at 91 % transmittance, σ>260 S cm^?1) and were successfully integrated as flexible electrodes in OLED and OPV devices.     

用CdSe/ZnS量子点提高体异质结有机太阳电池的效率

通过掺杂吸收光谱在可见光波段的量子点可提高聚合物对可见光的吸收,因此掺杂CdSe/ZnS核-壳结构量子点(CQDs)能提高聚(3-己基噻吩):[6,6]-苯基-C61-丁酸甲酯(P3HT:PCBM)体异质结太阳电池的能量转换效率.本文研究了CdSe/ZnS量子点在P3HT:PCBM中的不同掺杂比例及其表面配体对太阳电池光伏性能的影响,优化器件ITO(氧化铟锡)/PEDOT:PSS(聚(3,4-乙撑二氧噻吩:聚苯乙烯磺酸)/P3HT:PCBM:(CdSe/ZnS)/Al的能量转换效率达到了3.99%,与相同条件下没有掺杂量子点的参考器件ITO/PEDOT:PSS/P3HT:PCBM/Al相比,其能量转换效率提高了45.1%.     

Water soluble amino grafted silicon nanoparticles and their use in polymer solar cells

Stable aqueous amino-grafted silicon nanoparticles(SiNPs-NH2) were prepared via one-pot solution method. By grafting amino groups on the particle surface, the dispersion of SiNPs in water became very stable and clear aqueous solutions could be obtained. By incorporating SiNPs-NH2 into the hole transport layer of poly(3,4-ethylenedioxythiophene)/polystyrene sulfonic acid(PEDOT:PSS), the performance of polymer solar cells composed of poly[2-methoxy,5-(2'-ethylhexyloxy)-1,4-phenylene vinylene](MEH-PPV):[6,6]-phenyl-C61-butyric acid methyl ester(PCBM) as active layer can be improved. SiNPs-NH2 are dispersed uniformly in the PEDOT:PSS solution and help form morphologies with small-sized domains in the PEDOT:PSS film. SiNPs-NH2 serve as screens between conducting polymer PEDOT and ionomer PSS to improve the phase separation and charge transport of the hole transport layer. As a result, the sheet resistance of PEDOT:PSS thin films is decreased from(93 ± 5) × 105 to(13 ± 3) × 105 ?/□. The power conversion efficiency(PCE) of polymer solar cells was thus improved by 9.8% for devices fabricated with PEDOT:PSS containing 1 wt% of SiNPs-NH2, compared with the devices fabricated by original PEDOT:PSS.     

Plasticizer and catalyst co-functionalized PEDOT:PSS enables stretchable electrochemical sensing of living cells

Recently, stretchable electrochemical sensors have stood out as a powerful tool for the detection of soft cells and tissues, since they could perfectly comply with the deformation of living organisms and synchronously monitor mechanically evoked biomolecule release. However, existing strategies for the fabrication of stretchable electrochemical sensors still face with huge challenges due to scarce electrode materials, demanding processing techniques and great complexity in further functionalization. Herein, we report a novel and facile strategy for one-step preparation of stretchable electrochemical biosensors by doping ionic liquid and catalyst into a conductive polymer (poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate), PEDOT:PSS). Bis(trifluoromethane) sulfonimide lithium salt as a small-molecule plasticizer can significantly improve the stretchability and conductivity of the PEDOT:PSS film, and cobalt phthalocyanine as an electrocatalyst endows the film with excellent electrochemical sensing performance. Moreover, the functionalized PEDOT:PSS retained good cell biocompatibility with two extra dopants. These satisfactory properties allowed the real-time monitoring of stretch-induced transient hydrogen peroxide release from cells. This work presents a versatile strategy to fabricate conductive polymer-based stretchable electrodes with easy processing and excellent performance, which benefits the in-depth exploration of sophisticated life activities by electrochemical sensing.

A facile strategy for constructing stretchable sensors with excellent mechanical, electrochemical and biocompatible performance is developed, and in situ inducing and monitoring of stretch-evoked H₂O₂ release from cells has been successfully achieved.     

Development of flexible zinc–air battery with nanocomposite electrodes and a novel separator

In this paper, we present the development of flexible zinc–air battery. Multiwalled carbon nanotubes(MWCNTs) were added into electrodes to improve their performance. It was found that MWCNTs were effective conductive additive in anode as they bridged the zinc particles. Poly(3,4-ethylenedioxythiophene)polystyrene sulfonate(PEDOT:PSS) was applied as a co-binder to enhance both the conductivity and flexibility. A poly(acrylic acid)(PAA) and polyvinyl alcohol(PVA) coated paper separator was used to enhance the battery performance where the PVP–PAA layer facilitated electrolyte storage. The batteries remained functional under bending conditions and after bending. Multiple design optimizations were also carried out for storage and performance purposes.     

Lithium Polystyrene Sulfonate as a Hole Transport Material in Inverted Perovskite Solar Cells

Despite the exceptional efficiency of perovskite solar cells (PSCs), further improvements can be made to bring their power conversion efficiencies (PCE) closer to the Shockley-Queisser limit, while the development of cost-effective strategies to produce high-performance devices are needed for them to reach their potential as a widespread energy source. In this context, there is a need to improve existing charge transport layers (CTLs) or introduce new CTLs. In this contribution, we introduced a new polyelectrolyte (lithium poly(styrene sulfonate (PSS))) (Li:PSS) polyelectrolyte as an HTL in inverted PSCs, where Li⁺ can act as a counter ion for the PSS backbone. The negative charge on the PSS backbone can stabilize the presence of p-type carriers and p-doping at the anode. Simple Li:PSS performed poorly due to poor surface coverage and voids existence in perovskite film as well as low conductivity. PEDOT:PSS was added to increase the conductivity to the simple Li:PSS solution before its use which also resulted in lower performance. Furthermore, a bilayer of PEDOT:PSS and Li:PSS was employed, which outperformed simple PEDOT:PSS due to high quality of perovskite film with large grain size also the large electron injection barrier (ϕ_e) impeded back diffusion of electrons towards anode. As a consequence, devices employing PEDOT:PSS / Li:PSS bilayers gave the highest PCE of 18.64%.     

Contact optimization in polymer light‐emitting diodes

To fully exploit the properties of light‐emitting polymers (LEPs) in electroluminescent applications, it is of paramount importance to develop efficient electrical contacts. An ideal electrode is highly conductive, stable, provides a low barrier to carrier injection, and does not degrade the LEP upon contact. It is difficult to find a single homogeneous material that satisfies all of these requirements. Hence, contact optimization has often required the development of multilayer structures. In particular, indium tin oxide covered by a film of poly(ethylene‐dioxythiophene):poly(styrene sulfonic acid) {ITO/PEDOT:PSS} has become a favorite combination for the transparent anode, and heterostructures of LiF and CsF with metals (Al and Ca) have proven to be efficient electron‐injecting contacts. Here we review our progress in the understanding of the operation of light‐emitting diodes incorporating such contacts, in particular by gauging the materials' energy‐level lineup via electroabsorption measurements. Among the series of LEDs investigated, using a high‐energy‐gap blue polyfuorene polymer, CsF/Ca/Al and LiF/Ca/Al electrodes lead to the best improvements in electron injection. The most promising performance for applications, where a high luminance (～1600 cd/m² at 5 V) is also accompanied by a high maximum efficiency (～3 lm/W), was obtained with LiF/Ca/Al cathodes and ITO/PEDOT:PSS anodes. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 2649–2664, 2003     

Vacuum-free fabrication of high-performance semitransparent perovskite solar cells via e-glue assisted lamination process

From a base material of conductive polymer(poly-(3,4-ethylenedioxythiophene):poly(styrenesulfonate),PEDOT:PSS),a flexible and high-conductivity(as low as 45Ω/sq)transparent electrode was fabricated on polydimethylsiloxane elastomer by an acid treatment and transfer process.Combined with the D-sorbitol-doped PEDOT:PSS electric glue,we successfully demonstrated a vacuum-free and ambient lamination fabrication process for semi-transparent perovskite solar cells using triple cation Cs_(0.05)(MA_(0.17)FA_(0.83))_(0.95)Pb(I_(0.83)Br_(0.17))_3perovskite.By this manufacturing-friendly lamination process,we fabricated semitransparent perovskite solar cell devices with power conversion efficiencies up to 16.4%and variable transparencies.     

左旋多巴和N,N-二甲基亚砜共掺杂PEDOT:PSS作为空穴传输层的高性能p-i-n型钙钛矿太阳能电池

在p-i-n型的钙钛矿太阳能电池中,聚3, 4-乙烯二氧噻吩：聚苯乙烯磺酸盐(PEDOT:PSS)作为最常用的空穴传输层(HTL)材料之一,由于其存在着吸湿性强以及能级与钙钛矿层不匹配等缺点,限制了它的应用。基于此,本文拟采用将左旋多巴(DOPA)和N, N-二甲基亚砜(DMSO)共同掺杂于PEDOT:PSS作为HTL的简单方法制备高性能p-i-n型钙钛矿太阳能电池。研究结果表明,DOPA和DMSO共掺杂PEDOT:PSS可以有效的调节HTL的能级并提高其导电性,器件的能量转化效率由13.35%显著提高到了17.54%。进一步研究发现,相比于未掺杂或单一掺杂的PEDOT:PSS,在DOPA和DMSO共掺杂的PEDOT:PSS上更有利于生长大尺寸、高结晶度的钙钛矿晶体;同时稳态/瞬态荧光和交流阻抗测试表明器件的内部载流子分离和传输更加有效。