Lithium manganese oxide as an effective buffer layer between organic and metal layers in organic light-emitting devices

Abstract

Tris(8-hydroxyquinolinato)aluminum (Alq(3))-based organic light-emitting devices using a thermally deposited lithium manganese oxide layer between aluminum (Al) cathode and Alq(3) have been fabricated. The highest luminance efficiency obtained with a 1-nm-thick LiMnxOy layer is very similar to that of the device with 1-nm-thick LiF. However, the device with an 18 nm LiMnxOy layer obtained a longer operational stability although the luminance efficiency is lower. The improvements are attributed to lithium extractions of the lithium manganese oxide layer and the interfacial properties between Alq(3) and Al are discussed. (c) 2006 American Institute of Physics.