Optics and Photonics Society of Iran

The structure of flexible organic light emitting diodes (OLEDs) consists of an organic electro luminescence materials layer and conductive or semi-conductive polymers layer on the flexible transparent substrate, which emit light in response to electric current. In this study, various water soluble inks based on PEDOT: PSS which have different surface tension were formulated. The substrate surface energy that was printed with formulated inks was 49 dyne/cm. The results show that the altering inks surface tension has significant effect on the printed film properties and quality. The optimum amount of surface tension was about 47 dyne/cm along with the good quality of ink-jet printed film. The other properties of OLEDs such as transparency and lightening were acceptable.