Two Photolithographic Patterning Schemes for PEDOT:PSS and their Applications in Organic Light Emitting Diodes

Poly(3,4-ethylenedioxythio-phene):poly(styrenesulfonate) (PEDOT:PSS) is a promising conductive polymer in future flexible applications. To apply PEDOT:PSS into organic electronic devices, patterning processes are essential. Here, two photolithographic patterning schemes are introduced, namely fluorinated materials and silver interlayers. With hydrofluoroethers (HFEs) solvents and fluorinated photoresist, PEDOT:PSS can be patterned down to micro scales. Using a silver thin film to protect PEDOT:PSS surface, traditional photolithographic materials can be applied for PEDOT:PSS patterning. These two patterning processes do not obviously influence the electrical characteristics of PEDOT:PSS, and patterned conductive PEDOT:PSS is successfully applied to organic light-emitting diodes (OLEDs) as anodes. These patterning schemes can easily be used on large substrates, and high-resolution flexible OLED strips are also demonstrated. These results imply that the proposed PEDOT:PSS patterning schemes here have great potential to be employed in organic electronic devices.