54.3: Realization of Uniform OLED Pixels based on Multi‐nozzle by Inkjet printing

Inkjet printing has been used as an additive manufacturing method to fabricate organic light emitting diode (OLED). By changing the type and proportion of the solvent of the inks and adjusting the printing parameters of the ink droplets, uniform ejection of multi‐nozzle is achieved and the volume deviation of the jet is controlled at about 5% when poly(3,4‐ethy lenedioxythiohene) : poly (styrenesulfonate) (PEDOT:PSS), as the hole injection layer materials, was dissolved in isopropanol and ethylene glycol (volume ratio 2: 1). Moreover, the OLED devices of monochrome pixel was fabricated based on the multi‐nozzle, and the turn‐on voltage is reduced to 3.1v along with the improvement of the brightness and efficiency of the device.