Evaluation of thin film passivation using inorganic Mg–Zn–F heterointerface for polymer light emitting diode

In this study, we manufactured Mg–Zn–F targets using magnesium fluoride (MgF2) and zinc (Zn). The passivation films were deposited on a poly-ethylenenaphthalate (PEN) substrate using a radio-frequency magnetron sputter. The thickness of the manufactured passivation film was 120 nm. Among the three targets tested, the 4:6 weight target of MgF2 to Zn resulted in films with the highest Zn content that would increase the packing density of the thin film. The water vapor transmission rate of a 120 nm Mg–Zn–F film prepared from this target and inserted between two 40 nm MgF2 interlayers on PEN was 2.9 × 10− 2 g/(m2 day) at a relative humidity of 90% and a temperature 38 °C. Its optical transmittance was approximately 80%.