Effect of thickness on the electrical properties of PEDOT:PSS/Tween 80 films

The lower material and manufacturing costs of conductive polymers, particularly PEDOT:PSS, compared to indium tin oxide have led to significant research into their use in optoelectric devices. In this study, improvements of the electrical properties of PEDOT:PSS and PEDOT:PSS/Tween 80 via the production of multilayered films were investigated. A single layer of pristine PEDOT:PSS was found to give a sheet resistance of 1639 ohm-1. The application of an additional three layers reduced this value to 29 ohm-1, corresponding to an increase in conductivity from 2.6 to 18.3 Scm-1. A similar trend was also found with formulations containing Tween 80. X-ray diffraction and Raman spectroscopy showed that the additional layers increased the crystalline order and induced a slight benzoid to quinoid shift. Surface profiling showed progressive increases in surface roughness with each additional layer of pristine PEDOT:PSS; however, this was mitigated by the presence of Tween 80 in the formulations. This study explores enhanced electrical properties in conductive polymers, particularly PEDOT:PSS, by creating multilayered films. Initial findings show a sheet resistance of 1639 ohm-1 for a single layer, but applying three additional layers reduces it to 29 ohm-1, boosting conductivity from 2.6 to 18.3 Scm-1. Similar improvements are observed with formulations containing Tween 80. Analysis via X-ray diffraction and Raman spectroscopy indicates increased crystalline order and a benzoid to quinoid shift. Surface profiling reveals growing roughness with additional PEDOT:PSS layers, partially mitigated by Tween 80.