Highly\nStretchable and Highly Conductive PEDOT:PSS/Ionic\nLiquid Composite Transparent Electrodes for Solution-Processed Stretchable\nElectronics

Abstract

Stretchable conductive materials\nhave received great attention\nowing to their potential for realizing next-generation stretchable\nelectronics. However, the simultaneous achievement of excellent mechanical\nstretchability and high electrical conductivity as well as cost-effective\nfabrication has been a significant challenge. Here, we report a highly\nstretchable and highly conducting polymer that was obtained by incorporating\nan ionic liquid. When 1-ethyl-3-methylimidazolium tetracyanoborate\n(EMIM TCB) was added to an aqueous conducting polymer solution of\npoly­(3,4-ethylenedioxythiophene):poly­(styrenesulfonate) (PEDOT:PSS),\nit was found that EMIM TCB acts not only as a secondary dopant but\nalso as a plasticizer for PEDOT:PSS, resulting in a high conductivity\nof >1000 S cm^–1 with stable performance at tensile\nstrains up to 50% and even up to 180% in combination with the prestrained\nsubstrate technique. Consequently, by exploiting the additional benefits\nof high transparency and solution-processability of PEDOT:PSS, we\nwere able to fabricate a highly stretchable, semitransparent, and\nwholly solution-processed alternating current electroluminescent device\nwith unimpaired performance at 50% strain by using PEDOT:PSS/EMIM\nTCB composite films as both bottom and top electrodes.