Printable Silver Nanowire and PEDOT:PSS Nanocomposite\nInk for Flexible Transparent Conducting Applications

Abstract

Patterned\ndeposition of highly flexible transparent conducting\nmaterials is essential to realize stretchable optoelectronic devices.\nSilver nanowires (NWs) are suitable for these applications because\nthey possess high electrical conductivity and good optical transparency.\nHowever, NWs have poor surface adhesion and large roughness. Embedding\nthem in a conducting polymer, such as poly­(3,4-ethylenedioxythiophene):\npolystyrene sulfonate (PEDOT:PSS), is one way to overcome these disadvantages\nwithout affecting the optoelectronic properties. However, this is\nnormally a two-step deposition process and difficult to pattern directly.\nIn this work, we have formulated a stable and printable nanocomposite\nink consisting of Ag NWs and PEDOT:PSS. This ink can be directly used\nfor patterned deposition in a single-step process. The printed film\nshows 86% transparency and 23 Ω/sq sheet resistance, which is\nsuitable for flexible transparent electrode applications. The printed\nfilm shows good adhesion and excellent stability to mechanical deformation,\nwith less than 20% resistance variation after 10,000 bending cycles.\nThe nanocomposite also exhibits improved thermal stability, planarity,\nreduced contact resistance, and good optical transparency when compared\nto pure Ag NWs. We demonstrate suitability of this nanocomposite using\ntwo applications −a printed transparent flexible antenna radiating\nat Wi-Fi frequencies and a printed transparent flexible heater suitable\nfor antifogging applications. The nanocomposite properties make it\nsuitable as a transparent electrode in flexible optoelectronic devices\nsuch as photovoltaics and light-emitting diodes.