An Electrochemical Gelation Method for Patterning Conductive PEDOT:PSS Hydrogels

Due to their high water content and macroscopic connectivity, hydrogels made from the conducting polymer PEDOT:PSS are a promising platform from which to fabricate a wide range of porous conductive materials that are increasingly of interest in applications as varied as bioelectronics, regenerative medicine, and energy storage. Despite the promising properties of PEDOT:PSS‐based porous materials, the ability to pattern PEDOT:PSS hydrogels is still required to enable their integration with multifunctional and multichannel electronic devices. In this work, a novel electrochemical gelation (“electrogelation”) method is presented for rapidly patterning PEDOT:PSS hydrogels on any conductive template, including curved and 3D surfaces. High spatial resolution is achieved through use of a sacrificial metal layer to generate the hydrogel pattern, thereby enabling high‐performance conducting hydrogels and aerogels with desirable material properties to be introduced into increasingly complex device architectures.     

Stretchable Conductive Polymers and Composites Based on PEDOT and PEDOT:PSS

The conductive polymer poly(3,4‐ethylenedioxythiophene) (PEDOT), and especially its complex with poly(styrene sulfonate) (PEDOT:PSS), is perhaps the most well‐known example of an organic conductor. It is highly conductive, largely transmissive to light, processible in water, and highly flexible. Much recent work on this ubiquitous material has been devoted to increasing its deformability beyond flexibility—a characteristic possessed by any material that is sufficiently thin—toward stretchability, a characteristic that requires engineering of the structure at the molecular‐ or nanoscale. Stretchability is the enabling characteristic of a range of applications envisioned for PEDOT in energy and healthcare, such as wearable, implantable, and large‐area electronic devices. High degrees of mechanical deformability allow intimate contact with biological tissues and solution‐processable printing techniques (e.g., roll‐to‐roll printing). PEDOT:PSS, however, is only stretchable up to around 10%. Here, the strategies that have been reported to enhance the stretchability of conductive polymers and composites based on PEDOT and PEDOT:PSS are highlighted. These strategies include blending with plasticizers or polymers, deposition on elastomers, formation of fibers and gels, and the use of intrinsically stretchable scaffolds for the polymerization of PEDOT.     

Improvement of organic solar cell efficiency by solution-processed doping of pentacene in PEDOT:PSS layer

In the current research, organic solar cells (OSCs) with various concentrations of pentacene in Poly(ethylenedioxythiopene):Poly(styrenesulfonate) (PEDOT:PSS) interface layer were investigated for better hole extraction. The ITO/Pentacene?+?PEDOT:PSS/P3HT:PCBM/Al-fabricated solar cell fabricated via brush coating provides superior photovoltaic, electrical and optical characteristics when compared with the ITO/PEDOT:PSS/P3HT:PCBM/Al solar cell. The ITO/Pentacene?+?PEDOT:PSS/P3HT:PCBM/Al solar cells deliver a V_OC ~350?mV and 2.57% efficiency. It is observed that the optimized concentration of pentacene doping in PEDOT:PSS layer, along with an active layer of P3HT and PC₆₀BM, doubles the efficiency of the device, when compared with pristine PEDOT:PSS layer. The degradation studies of the fabricated bulk heterojunction OSCs reveal that the degrading abilities of ITO/Pentacene?+?PEDOT:PSS/P3HT:PCBM/Al solar cells are 60% more better than those of ITO/PEDOT:PSS/P3HT:PCBM/Al devices. Thus, this work will ultimately contribute toward fully solution processed painted device, which will provide low-cost manufacturing and improved stability of pentacene-based organic photovoltaics.     

PEDOT∶PSS薄膜在有机光电子领域的研究进展

PEDOT∶PSS薄膜的导电率高、透光性好、且稳定易加工,在有机光电子领域,特别是在有机太阳能电池和有机发光二极管领域得到了广泛的应用研究。从PEDOT∶PSS薄膜的应用和改性两个方面综述了近10年PEDOT∶PSS薄膜在有机太阳能电池和有机发光二极管领域的研究成果,初步展望了其以后的发展方向。     

Room-Temperature-Formed PEDOT:PSS Hydrogels Enable Injectable,Soft, and Healable Organic Bioelectronics

There is an increasing need to develop conducting hydrogels for bioelectronic applications. In particular, poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) hydrogels have become a research hotspot due to their excellent biocompatibility and stability. However, injectable PEDOT:PSS hydrogels have been rarely reported. Such syringe-injectable hydrogels are highly desirable for minimally invasive biomedical therapeutics. Here, an approach is demonstrated to develop injectable PEDOT:PSS hydrogels by taking advantage of the room-temperature gelation property of PEDOT:PSS. These PEDOT:PSS hydrogels form spontaneously after syringe injection of the PEDOT:PSS suspension into the desired location, without the need of any additional treatments. A facile strategy is also presented for large-scale production of injectable PEDOT:PSS hydrogel fibers at room temperature. Finally, it is demonstrated that these room-temperature-formed PEDOT:PSS hydrogels (RT-PEDOT:PSS hydrogel) and hydrogel fibers can be used for the development of soft and self-healable hydrogel bioelectronic devices.     

二元溶剂掺杂的PEDOT/PSS在纸上的导电性研究

目的 提高纸张基底上有机材料的导电性。方法 以有机半导体材料聚3,4-乙撑二氧噻吩/聚苯乙烯磺酸盐（PEDOT/PSS）为导电材料,以不同纸张（硫酸纸、胶版纸、复印纸和喷墨打印纸）做基底,利用二甲基亚砜（DMSO）、异丙醇（IPA）二元溶剂掺杂PEDOT/PSS溶液,对比分析PEDOT/PSS涂层在纸张上的导电性能,同时探讨多层单一浓度、多层降浓度、多层升浓度涂布对涂层导电性能的影响。结果 在PEDOT/PSS溶液中掺杂单一溶剂DMSO,添加DMSO体积分数为5%时,可以得到最佳的导电性能;通过二元溶剂掺杂优化PEDOT/PSS溶液在纸上的成膜,最佳体积分数为23%;同时在不同浓度配方下,喷墨打印纸的涂层导电性能最好;多层降浓度涂布可以将涂层方阻由13 kΩ/□降为0.255 kΩ/□。结论 利用二元溶剂掺杂能够在很大程度上提高了PEDOT/PSS导电涂层的导电性能;表面致密、平滑及透气性低的纸张是最佳的基底选择;多层降浓度涂布是最佳方式。     

PEDOT/PSS的合成及在抗静电涂料中的应用

利用过硫酸铵为氧化剂通过化学氧化法合成了聚(3,4-亚乙基二氧噻吩)/聚对苯乙烯磺酸(PEDOT/PSS)。红外光谱证明了PEDOT/PSS的合成。研究了PSS、过硫酸铵的用量,理论固含量的大小对PEDOT/PSS的导电性能及粒径的影响。发现化学氧化法制备PEDOT/PSS较佳的反应条件:PSS中磺酸基与单体的摩尔比为2∶1;过硫酸铵与单体的摩尔比为1.5∶1;固含量范围为2.8%~4.2%。分析了PEDOT/PSS胶粒形成的机理。并用PEDOT/PSS配制成抗静电涂料,在聚丙烯(PP),聚对苯二甲酸二醇酯(APET),聚苯乙烯(PS)基材上涂布测得表面电阻。表面电阻范围为107Ω~108Ω,具有良好的透明性与附着力。     

溴掺杂对PEDOT/PSS薄膜性能的影响及机理研究

为改善聚乙撑二氧噻吩∶聚（对苯乙烯磺酸）根阴离子（PEDOT/PSS）薄膜的光学及电学性能,采用共混-旋涂法在石英玻片上制备出溴掺杂的PEDOT/PSS透明导电膜,并就其掺杂导电机理进行了探讨.结果表明：经微量溴掺杂后的PEDOT/PSS薄膜,其透光性能与导电性能均得到提高;质量分数6%溴掺杂条件下,薄膜透光率为95....     

Local Degradation of PEDOT:PSS on Silicon Nanostructures Using Scanning Electrochemical Microscopy

Conducting polymers show attractive characteristics as electrode materials for micro-electrochemical energy storage (MEES). However, there is a lack of characterization techniques to study conjugated/conducting polymer-based nanostructured electrodes. Here, scanning electrochemical microscopy (SECM) is introduced as a new technique for in situ characterization and acceleration of degradation processes of conducting polymers. Electrodes of PEDOT:PSS on flat silicon, silicon nanowires (SiNWs) and silicon nanotrees (SiNTrs) are analyzed by SECM in feedback mode with approach curves and chronoamperometry. The innovative degradation method using SECM reduces the time required to locally degrade polymer samples to a few thousand seconds, which is significantly shorter than the time usually required for such studies. The degradation rate is modeled using Comsol Multiphysics. The model provides an understanding of the phenomena that occur during degradation of the polymer electrode and describes them using a mathematical constant A₀ and a time constant τ.     

碳纳米管和二甲基亚砜对钙钛矿太阳电池中PEDOT:PSS空穴传输层的协同影响

聚(3,4-亚乙二氧基噻吩)-聚(苯乙烯磺酸)(PEDOT:PSS)是平面结构钙钛矿太阳电池中空穴传输层的典型材料, 为了改善其导电性能以及促进后续钙钛矿层的生长, 本文将碳纳米管(CNTs)和二甲基亚砜(DMSO)同时引入PEDOT:PSS进行共修饰。结果表明: CNTs和DMSO在CNT-DMSO-PEDOT:PSS共修饰膜中展现了优异的协同效应。均匀贯穿于基体且几近网格状的CNTs具有促进后续钙钛矿层生长及降低共修饰膜方块电阻的功能; DMSO扮演着加强共修饰膜的导电能力及控制CNTs流失的角色。因此, 与单修饰膜相比, 共修饰膜不仅能更有效地传输电荷, 而且其表面生长的钙钛矿层晶粒尺寸更大, 覆盖率更高。此外, 共修饰膜在可见光范围内仍然保持优异的透光率, 550 nm波长处的透光率为88.8%。组装成器件后, 共修饰膜的光电转换效率(PCE)为5.75%, 远高于CNTs和DMSO单修饰膜及纯PEDOT:PSS膜, 后三者的PCE分别为3.01%、2.03%和1.30%。     

Synthesis and purification of long copper nanowires. Application to high performance flexible transparent electrodes with and without PEDOT:PSS

We demonstrate the hydrothermal synthesis of long copper nanowires based on a simple protocol. We show that the purification of the nanowires is very important and can be achieved easily by wet treatment with glacial acetic acid. Fabrication of random networks of purified copper nanowires leads to flexible transparent electrodes with excellent optoelectronic performances （e.g., 55 Ω/sq. at 94% transparency）. The process is carried out at room temperature and no post-treatment is necessary. Hybrid materials with the conductive polymer PEDOT：PSS show similar properties （e.g., 46 Ω/sq, at 93% transparency）, with improved mechanical properties. Both electrodes were integrated in capacitive touch sensors.