Fibrillary gelation and dedoping of PEDOT:PSS fibers for interdigitated organic electrochemical transistors and circuits
Young Jin Jo, Soo Young Kim, Jeong Hun Hyun, Byeonghak Park, Seunghwan Choy, Gyan Raj Koirala, Tae‐il Kim
Abstract
Abstract As one of conducting polymers, PEDOT:PSS, is commonly used in organic electronics, especially for bioelectronics due to its advantages such as high electrical and ionic conductivity, solution-processability and biocompatibility. Creating bioelectronics with the PEDOT:PSS requires advanced techniques to obtain physical/chemical modification of the PEDOT:PSS for improved performance and various applications. To satisfy these demands, fibrillary gelation of PEDOT:PSS by injection to choline acetate, an ionic liquid, with a constant flow rate was used in this study to make a conductive fiber and improve characteristics of PEDOT:PSS. Conductive fibers by fibrillary gelation showed enhanced electrical conductivity of about 400 S cm −1 and volumetric capacitance of about 154 F cm −3 which would be strongly beneficial to be utilized for organic electrochemical transistors (OECTs), resulting in a high transconductance of 19 mS in a depletion-mode. Moreover, dedoping of the conductive fibers by PEI (polyethyleneimine) enabled the creation of enhancement-mode OECTs. Interdigitated inverters were then fabricated by connecting depletion and enhancement-mode OECTs. These results demonstrate that these conductive fibers and electronic-textiles are suitable candidates for applications in bio-integrated electronics.