Interface engineering in preparation of organic surface-emitting diodes
- 24 May 1999
- journal article
- Published by AIP Publishing in Applied Physics Letters
- Vol. 74 (21) , 3209-3211
- https://doi.org/10.1063/1.124107
Abstract
Surface-emitting organic light emitting diode(OLED) was prepared by sputter deposition of indium-tin-oxide on a buffered organic layer structure. Confirming a previous report, a thin film of copper phthalocyanine (CuPc) was found to be a useful buffer layer in preventing sputter damage to the OLED layer structure, particularly the underlying Alq emissive layer. However, the CuPc layer forms an electron-injection barrier with the Alq layer, resulting in increased electron-hole recombination in the nonemissive CuPc layer, and thus a substantial reduction in electroluminescence efficiency. Incorporation of Li at the CuPc/Alq interface was found to reduce the injection barrier at the interface and recover the overall device efficiency with good surface emission characteristics.Keywords
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