Devendra Singh1 Gilles Lubineau1

1, King Abdullah University of Science and Technology, Thuwal, , Saudi Arabia

The design of new electronic system featuring flexibility and stretchability requires using advanced materials and microstructure. Classical inorganic materials are conductive but brittle in nature. On another side, organic materials are flexible but comparatively less conductive and are sensitive to environmental conditions. Here, we propose a novel approach to integrate the advantages of both inorganic (Indium tin oxide) as well as organic materials, here PEDOT:PSS (poly-(3,4 ethylenedioxythiophene): poly (styrene sulfonic acid)) as conducting polymer, for their conductive and flexible intrinsic properties, respectively. In this work, a PEDOT:PSS buffer layer is used between ITO layer and PET [polyethylene terephthalate] substrate such that during the deformation of the film, the stacked system retains its high conductivity with strong stability. The reason for using a PEDOT:PSS buffer layer is to substantially reduce the detrimental effects of cracks in the ITO layer in terms of an overall conductivity of the system. The highly conductive and transparent ITO films were sputter deposited on PET substrates at room temperature, and different configurations (with and without annealing and/or an intermediate layer of PEDOT:PSS) has been studied extensively. Structural, optical, mechanical and morphological studies have been carried out to understand the behavior of involved layers qualitative and quantitatively. We find that integration of an ITO thin film with PEDOT:PSS buffer layer results in robust synergetic behavior, showing a relatively low initial electrical sheet resistance that is very stable even under strong bending (value of bending radii down to 2.5 mm, repeated cycles up to 1000 cycles). This high stability can be attributed to an improvement of the electrical transfer at the delaminated interfaces due to supporting buffer layer. Results show that this highly conductive, flexible and transparent platforms can be used for advanced flexible devices.