Hou Saiyin, Chen Haiqi, Lv Dong, Li Wei, Liu Xuelei, Zhang Qiang, Yu Xinhong, Han Yanchun
State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, PR China.
School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei 230026, PR China.
ACS Appl Mater Interfaces. 2023 Jun 14;15(23):28503-28515. doi: 10.1021/acsami.3c03378. Epub 2023 Jun 5.
Inkjet-printed conductive polymer PEDOT:PSS films have provided a new developing direction for realizing the stretchable transparent electrodes in optoelectronic devices. However, their conductivity and stretchability are limited as the presence of insulating PSS chains, rigid PEDOT conjugated backbone, and stronger inter-chain interactions in the pristine polymer, respectively. Here, we report a PEDOT:PSS film with preferable electrical and mechanical performances by inkjet-printing the formulated printable ink containing PEDOT:PSS, formamide (FA), d-sorbitol (SOR), sodium dodecyl benzene sulfonate (DBSS), and ethylene glycol (EG). The inkjet-printed uniform PEDOT:PSS film exhibits a high conductivity of 1050 S/cm and sheet resistance of less than 145 Ω/sq on both rigid and flexible substrates. Moreover, the resistance can remain stable after 200 cycles of stretching at 55% strain. The film also presents good stability during repetitive stretching-releasing cycles. The significantly enhanced conductivity of the film lies on the conformational transition of the backbone by secondary doping and post-treatment with FA as well as removing the excess PSS components after phase separation between PEDOT and PSS. Meanwhile, SOR serves as a plasticizer to break the original hydrogen bonds between PSSH chains and provides larger free volume for polymer chain extension, which gives the PEDOT:PSS film the ability to tolerant cyclic tension. This is one of the optimal performances currently reported for inkjet-printed stretchable PEDOT:PSS films. The inkjet-printed PEDOT:PSS film with high conductivity, stretching properties, as well as good biocompatibility exhibits promising prospects as anodes on optoelectronic devices.
喷墨打印的导电聚合物聚（3,4-乙撑二氧噻吩）：聚（苯乙烯磺酸钠）（PEDOT:PSS）薄膜为实现光电器件中的可拉伸透明电极提供了一个新的发展方向。然而，由于原始聚合物中存在绝缘的PSS链、刚性的PEDOT共轭主链以及较强的链间相互作用，它们的导电性和拉伸性受到限制。在此，我们通过喷墨打印含有PEDOT:PSS、甲酰胺（FA）、d-山梨醇（SOR）、十二烷基苯磺酸钠（DBSS）和乙二醇（EG）的可打印油墨，报道了一种具有优异电学和力学性能的PEDOT:PSS薄膜。喷墨打印的均匀PEDOT:PSS薄膜在刚性和柔性基板上均表现出1050 S/cm的高电导率和小于145 Ω/sq的方块电阻。此外，在55%应变下拉伸200次循环后，电阻仍能保持稳定。该薄膜在反复拉伸-释放循环过程中也表现出良好的稳定性。薄膜导电性的显著提高在于通过二次掺杂和用FA后处理使主链发生构象转变，以及在PEDOT和PSS相分离后去除过量的PSS成分。同时，SOR作为增塑剂打破了PSSH链之间原有的氢键，并为聚合物链的伸展提供了更大的自由体积，这赋予了PEDOT:PSS薄膜承受循环张力的能力。这是目前报道的喷墨打印可拉伸PEDOT:PSS薄膜的最佳性能之一。具有高导电性、拉伸性能以及良好生物相容性的喷墨打印PEDOT:PSS薄膜作为光电器件的阳极具有广阔的应用前景。
