Ultra thin film encapsulation of organic light emitting diode on a plastic substrate

Abstract

We have carried out the fabrications of a barrier layer on a polyethersulfon (PES) film and organic tight emitting diode (OLED) based on a plastic substrate by means of atomic layer deposition (ALD). Simultaneous deposition of 30 nm Al-x film on both sides of the PES film gave a water vapor transition rate (WVTR) of 0.062 g/m(2)/day (@38 degrees C, 100% R.H.). Further, the double layer of 200 nm SiNx, film deposited by plasma enhanced chemical vapor deposition (PECVD) and 20 nm AlOx film by ALD resulted in a WVTR value lower than the detection limit of MOCON. We have investigated the OLED encapsulation performance of the double layer using the OLED structure of ITO / MTDATA (20 nm) / NPD (40 nm) / Al (60 nm) / LiF (1 nm) / Al (75 nm) on a plastic substrate. The preliminary life time to reach 91% of the initial luminance (1300 cd/m(2)) was 260 hours for the OLED encapsulated with 100 nm of PECVD-deposited SiNx and 30 nm of ALD-deposited AlOx.