Al2O3/Ag/Al2O3 multilayer thin film passivation prepared by plasma damage-free linear facing target sputtering for organic light emitting diodes

Abstract Al 2 O 3 /Ag/Al 2 O 3 multilayer passivation prepared by plasma damage-free linear facing target sputtering (LFTS) was investigated as a function of inserted Ag thickness. Using antireflection effect of the Ag layer that is sandwiched between dielectric Al 2 O 3 layers, we can obtain a transparent Al 2 O 3 /Ag/Al 2 O 3 multilayer passivation for organic light emitting diodes (OLEDs). It was found that insertion of the Ag layer with optimized thickness between Al 2 O 3 layers lead to improvement of the optical transparency and water vapor transmission rate of the Al 2 O 3 /Ag/Al 2 O 3 multilayer. In addition, current density–voltage–luminescence of an OLED passivated with Al 2 O 3 /Ag (10 nm)/Al 2 O 3 multilayer was similar to that of an OLED with nonpassivated sample, indicating that the performance of an OLED is not affected by high-density plasma during the LFTS process. Moreover, the lifetime to half initial luminance of an OLED passivated with Al 2 O 3 /Ag (10 nm)/Al 2 O 3 multilayer was longer than that of a nonpassivated sample.