Sequential Solution Polymerization of Poly(3,4-ethylenedioxythiophene) Using V2O5 as Oxidant for Flexible Touch Sensors

Rui Chen; Kuan Sun; Qi Zhang; Yongli Zhou; Meng Li; Yuyang Sun; Zhou Wu; Yuyang Wu; Xinlu Li; Jialei Xi; Chi Ma; Yiyang Zhang; Jianyong Ouyang

doi:10.1016/j.isci.2019.01.003

Sequential Solution Polymerization of Poly(3,4-ethylenedioxythiophene) Using V₂O₅ as Oxidant for Flexible Touch Sensors

iScience. 2019 Feb 22:12:66-75. doi: 10.1016/j.isci.2019.01.003. Epub 2019 Jan 5.

Authors

Rui Chen¹, Kuan Sun², Qi Zhang¹, Yongli Zhou¹, Meng Li¹, Yuyang Sun³, Zhou Wu³, Yuyang Wu⁴, Xinlu Li⁴, Jialei Xi⁵, Chi Ma⁵, Yiyang Zhang⁵, Jianyong Ouyang⁶

Affiliations

¹ MOE Key Laboratory of Low-grade Energy Utilization Technologies and Systems, School of Energy & Power Engineering, Chongqing University, Chongqing 400044, China.
² MOE Key Laboratory of Low-grade Energy Utilization Technologies and Systems, School of Energy & Power Engineering, Chongqing University, Chongqing 400044, China. Electronic address: kuan.sun@cqu.edu.cn.
³ MOE Key Laboratory of Dependable Service Computing in Cyber Physical Society, School of Automation, Chongqing University, Chongqing 400044, China.
⁴ School of Materials Science and Engineering, Chongqing University, Chongqing 400044, China.
⁵ Chengdu Mobius Technology, Sichuan 610015, China.
⁶ Department of Materials Science and Engineering, National University of Singapore, Singapore 117574, Singapore. Electronic address: mseoj@nus.edu.sg.

Abstract

Various in situ synthesis methods have been developed for the polymerization of 3,4-ethylenedioxythiophene monomers, such as electropolymerization, oxidative chemical vapor deposition, and vapor phase polymerization. Meeting industrial requirements through these techniques has, however, proven challenging. Here, we introduce an alternative method to fabricate highly conductive poly(3,4-ethylenedioxythiophene) (PEDOT) films in situ by solution means. The process involves sequential deposition of oxidants (V₂O₅ in this case) and monomers. Excess reactants and by-products can be completely removed from the PEDOT film by MeOH rinsing. The obtained PEDOT films possess good crystallinity and high doping level, with carrier concentration three orders of magnitude higher than that of the commercial product (PH1000, Heraeus GmbH). The electrical conductivity of the as-cast PEDOT film reaches up to 1,420 S/cm. In addition, this method is fully compatible with large-scale printing techniques. These PEDOT conducting films enable the realization of flexible touch sensors, which demonstrate superior flexibility and sensitivity.

Keywords: Chemistry; Electronic Materials; Polymer Chemistry.