Thin-film encapsulation of top-emission organic light-emitting devices with polyurea/Al<sub>2sub>O<sub>3sub> hybrid multi-layers

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• 作者：Young Gu Lee ; Yun-Hyuk Choi ; In Seo Kee ; Hong Shik Shim ; YongWan Jin ; Sangyoon Lee ; Ken Ha Koh ; Soonil Lee
• 关键词：Encapsulation ; Hybrid multi-layers ; Polyurea ; Top-emission OLED
• 刊名：Organic Electronics
• 出版年：2009
• 出版时间：November 2009
• 年：2009
• 卷：10
• 期：7
• 页码：1352-1355
• 全文大小：434 K

文摘

We developed a room-temperature encapsulation process based on multi-stack of ultra thin Al<sub>2sub>O<sub>3sub> and polyurea layers for top-emission organic light-emitting devices (TEOLEDs). Device structure, including a capping layer for refractive-index matching and a thick polyurea buffer layer, was optimized to enhance light extraction without distorting electroluminescence spectrum. The efficiency of a TEOLED encapsulated with 5 pairs of Al<sub>2sub>O<sub>3sub>(50 nm)/polyurea(20 nm) layers was better than that of a glass-encapsulated TEOLED, whereas their color coordinates were almost identical. Moreover, the half-decay lifetime of a TEOLED encapsulated with 5 pairs of Al<sub>2sub>O<sub>3sub>/polyurea layers was 86 % of that of a glass-encapsulated TEOLED. Water vapor transition rate of 5 pairs of Al<sub>2sub>O<sub>3sub>(50 nm)/polyurea(20 nm) layers on PET film was measured as low as 5 × 10<sup>−4sup> g/m<sup>2sup> day.