Ultra Thin Film Encapsulation of Organic Light Emitting Diode on a Plastic Substrate

We have carried out the fabrications of a barrier layer on a polyethersulfon (PES) film and organic light emitting diode (OLED) based on a plastic substrate by means of atomic layer deposition (ALD). Simultaneous deposition of 30 nm AlOx film on both sides of the PES film gave a water vapor transition rate (WVTR) of 0.062 g/m2/day (@38°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) / AlQ (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/m2) was 260 hours for the OLED encapsulated with 100 nm of PECVD‐deposited SiNx and 30 nm of ALD‐deposited AlOx.

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