Selective deposition of PEDOT/PSS on to flexible substrates and tailoring the electrical resistivity by post treatment

Purpose - This paper aims to describe two manufacturing techniques for selective patterning of Poly-3-4-ethyleneoxythiophene/poly-4-sytrensulfonate (PEDOT/PSS) for flexible electronic applications. The paper also includes methods to tailor the electrical conductivity of the patterned polymeric films. Design/methodology/approach - Line patterning and inkjet printing methods were used to pattern PEDOT/PSS onto mechanically flexible substrates including polyethylene terephthalate, polyimide and paper. Findings - PEDOT/PSS thin films with controlled spatial resolution and strong adhesion passing a laboratory Scotch-tape test were patterned onto flexible substrates using both line patterning and inkjet printing techniques. After annealing, the sheet resistivities of patterned PEDOT/PSS lines increased slightly. Treating the electrodes with ethylene glycol dramatically increased the electrical conductivity. Research limitations/implications - There has been extensive work on selective deposition of solution processable active materials onto mechanically flexible substrates. Many techniques including line patterning and inkjet printing are currently being used to fabricate devices for flexible electronic applications. However, there is a need for tailoring the electrical conductivity of the patterned polymeric active materials. Originality/value - In this study, two very cost effective methods for the selective deposition of the water soluble PEDOT/PSS onto flexible substrates with controlled spatial resolution and electrical conductivity are reported.