Increased Adhesion Force Due to Increased Conductivity in PEDOT:PSS/PEO Spun-coated Nanofilm

Abstract

We propose a novel method to tune the interfacial adhesive force (Fad) between PEDOT:PSS/PEO organic electroconductive polymer and Si3N4 (a ceramic) by decreasing the electron work function (EWF) and the electrical resistivity of the PEDOT:PSS/PEO nanosheet. By using the known method of preferential solvation using polar aprotic solvent (DMSO), we were able rearrange the spatial orientation of PSSH backbone chain in the polymer and increase the Density of States (DOS) and the electron hopping length (ξ') of the polymer, thus increasing its conductivity. As the material becomes more conductive, the formation of a dipole layer between the Schottky Diode system of PEDOT:PSS/PEO and Si3N4 is facilitated. This leads to the increased interaction between the two materials, raising the adhesive force by 35.8% with only 5% w/w DMSO addition to the polymer. This relatively simple treatment of PEDOT:PSS results in an interfacial adhesion or bonding strength. This approach is general, which would be applicable for enhancing interfacial bonding between two different types of material without atomic diffusion involved.