Sprayability Analysis of Pristine and Enhanced PEDOT:PSS Inks via Electrohydrodynamic Spray Deposition

Poly (3,4-ethylene dioxythiophene) polystyrene sulfonate (PEDOT:PSS) is a conductive polymer and versatile material to fabricate numerous organic electronic devices. PEDOT:PSS inks were studied and analyzed for their sprayability via Electrohydrodynamic (EHD) printing. Commercially obtained pristine PEDOT:PSS ink could not produce any decent cone-jet mode due to its high surface tension and viscosity. Two different surfactants – acetone and ethanol were then dispersed into PEDOT:PSS at different concentrations to enhance the sprayability of the PEDOT:PSS ink. Both modified PEDOT:PSS inks could produce a cone-jet mode of spraying, which is essential for EHD printing. The flow rates were tested between 10 - 20 μl/hr. These limits were established to prevent the splashing effect at a higher flow rate (>20μl/hr) and inks disintegrating at a lower flow rate 5μl/hr. PEDOT:PSS:Acetone and PEDOT:PSS:Ethanol with 50:50 and 75:25 ratios, respectively, produced the best performance in their respective categories.