Thin film encapsulation for organic light-emitting diodes using inorganic/organic hybrid layers by atomic layer deposition

Abstract

A hybrid nanolaminates consisting of Al2O3/ZrO2/alucone (aluminum alkoxides with carbon-containing backbones) grown by atomic layer deposition (ALD) were reported for an encapsulation of organic light-emitting diodes (OLEDs). The electrical Ca test in this study was designed to measure the water vapor transmission rate (WVTR) of nanolaminates. We found that moisture barrier performance was improved with the increasing of the number of dyads (Al2O3/ZrO2/alucone) and the WVTR reached 8.5 × 10−5 g/m2/day at 25°C, relative humidity (RH) 85%. The half lifetime of a green OLED with the initial luminance of 1,500 cd/m2 reached 350 h using three pairs of the Al2O3 (15 nm)/ZrO2 (15 nm)/alucone (80 nm) as encapsulation layers.Electronic supplementary materialThe online version of this article (doi:10.1186/s11671-015-0857-8) contains supplementary material, which is available to authorized users.

Low-temperature atomic layer deposition of Al2O3/alucone nanolaminates for OLED encapsulation

“…4. It was found that the water barrier properties were enhanced with the increase of the dyad ( 19 Commercially, in order to assure the minimum lifetime of most OLEDs at least for 10000 h, the WVTR should be less than 10 À6 g per m 2 per day. 2 Al 2 O 3 /alucone laminates with more number of dyads and thickness should be used.…”

“…However, the structure, e.g., the individual layer thickness and the number of stacks, is remained for further improvement. [18][19][20] In this work, Al 2 O 3 /alucone with maximum thickness of 102.5 nm have been fabricated using ALD/MLD under a low temperature of 90 C. The optical and moisture barrier performances were then investigated with respect to the individual layer thickness and the number of stacks. Finally, the barrier performance and three-dimensional conformality of Al 2 O 3 /alucone lms were conrmed as top barrier of OLED devices with uneven pixel dened layer (PDL).…”

Organic Flexible Electronics

“…Inorganic encapsulation materials, e.g., commercialized Al 2 O 3 , SiO x , and SiN x , show superior protection from moisture. However, they suffer from both factors of poor flexibility and pinhole defects in the layer surface . At present, inorganic/organic hybrid has been considered as one of the most effective barrier technologies of flexible OLEDs.…”

“…At present, inorganic/organic hybrid has been considered as one of the most effective barrier technologies of flexible OLEDs. Typical examples include ZnO/parylene C, SiN–acrylate–SiN, Al 2 O 3 /ZrO 2 /alucone, zinc‐tin‐oxide (ZTO)/ORMOCER/ZTO, polymer/graphite nanocomposites, etc. Specifically, a water vapor transmission rate (WVTR) of less than 10 −6 g m −2 d −1 and an oxygen transmission rate (OTR) as low as 10 −5 cm 3 m −2 d −1 should be achieved to develop sufficient barriers for OLEDs…”

High-Performance White Organic Light-Emitting Diodes Using Distributed Bragg Reflector by Atomic Layer Deposition

“…The DBR ZrO 2 /zircone films were deposited in the Beneq TFS-200 ALD reactor, which has been explained in another work [21]. Firstly, the sonication was conducted to clean the glass substrate, which was then put in detergent solution as well as deionized water in succession and then treated by UV ozone.…”