PEDOT:PSS conductivity enhancement through addition of the surfactant Tween 80

Replacement of indium tin oxide with the intrinsically conducting polymer poly(3,4–ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) has been of significant interest in recent years as a result of lower processing and material costs. In addition, the inclusion of addi-tives has been reported to enhance the conductivity, rheology and wettability of PEDOT:PSS fur-ther. In this study, Tween 80 is shown to decrease the sheet resistance of PEDOT:PSS films from approximately 1000 to 76 Ω□^-1 at a 2.67 wt% surfactant concentration. Through X-ray diffraction, Raman spectroscopy and atomic force microscopy, it is shown that the surfactant causes phase separation and structural ordering of the PEDOT and PSS components, leading to this improve-ment in conductivity. Furthermore, Tween 80 alters the rheological properties and decreases the surface tension of PEDOT:PSS, making coating onto common commodity polymers, often used as flexible substrates, more viable.