2008 Volume 36 Issue APLS Pages 1242-1245
Device-quality ITO by pulsed Nd:YAG laser, successfully used for Organic Light Emitting Device (OLED), was deposited at room temperature and 250 °C. Although the optical transmittance of > 90% is achieved in the visible range, the ITO film resistivity is too high to enable an efficient OLED, as compared to that reported for KrF laser deposited ITO. At 250 °C and laser wavelength of 355 nm, the ITO film resistivity decreased by 10x to 2 × 10-4 Ωcm while its optical transmittance was > 90 %. For PET, the heating temperature was limited to 150 °C and hence the ITO resistivity could only be decreased by a factor of 2 to 5 × 10-4 Ωcm. The thermally induced crystallization of ITO, which has a preferred <111> directional orientation texture, largely accounts for lowering of its film resistivity. The OLED was based on simple device structure of ITO/(PVK+TPD+Alq3)/Al, which output brightness was compared to that fabricated on the commercial ITO. Effet of an ultra-thin diamond-like carbon (DLC) layer in the OLED was investigated.