Spontaneous Patterning of Polymer Film by Teflon Thin Film and Spin Coating for Polymer Light-Emitting Diode

We have developed a selective coating technology for large-area polymer light-emitting devices (PLEDs). This can be done by using the different surface energy on the anode electrode. Teflon thin film can be used to make a hydrophobic surface (low surface energy) on the hydrophilic surface (high surface energy) of ITO for patterning of polymer film. Contact angle of ITO surface and Teflon coated one were 3 and 130°, respectively. In order to demonstrate PLED by spontaneous patterning of polymer film we have fabricated PLED consist of 4 and 8 elements in series on the same substrate. The voltage of the devices required to achieve a particular brightness scales approximately with the number of elements in series.