Transparent conducting AZO cosputtered ITO anode films grown by a dual target DC magnetron sputtering for OLEDs

Abstract

Transparent conducting Al-doped ZnO (AZO) cosputtered indium tin oxide indium tin oxide (ITO) electrodes (150 nm) were grown by dual target dc magnetron sputtering at room temperature for organic light-emitting diodes (OLEDs). It was found that the sheet resistance, resistivity, optical transmittance, figure of merit, and work function of AZO cosputtered ITO electrodes were significantly influenced by the dc power of the AZO target at constant dc power of the ITO target. Even though the structure of the AZO cosputtered ITO electrode is amorphous due to a low substrate temperature (similar to 50 degrees C), the AZO cosputtered ITO electrode shows an electrical resistivity of 4.6x10(-4) Omega cm, an optical transmittance of 85% (550 nm wavelength), a figure-of-merit value of 9.83x10(-3) Omega(-1), and a work function of 5.2 eV at 20 W of dc power of the AZO target. The current density and luminance of the OLED fabricated on the 20 W AZO cosputtered ITO anode are higher than that of the OLED with an amorphous ITO anode, indicating the possibility of the AZO cosputtered ITO electrode as an amorphous transparent conducting oxide for OLEDs.