Patternable Semi‐Transparent Cathode using Thermal Evaporation for OLED Display Applications

A new patternable semi-transparent metal cathode, Zn:Mg (4:1 and 10:1) using the thermal evaporation process for organic light-emitting diode (OLED) display applications is reported. A new Zn:Mg alloy film shows good surface morphology and almost no temperature effect on the shadow mask. The Zn:Mg layer with ratio of 4:1 and 10:1 shows sheet resistance of 33.2 and 39.2 omega (-1), respectively, at the thickness of 12 nm. The fabricated green top-emitting OLED (TEOLED) with Zn:Mg cathode shows current efficiency of 79.3 cd A(-1) and a color coordinates of (0.166, 0.755). These results show the possibility of high-quality cathode patterning for various OLED display and sensor applications.