Lee Young Joo, Li Xiaolong, Kang Da-Yeon, Park Seong-Sik, Kim Jinwoo, Choi Jeong-Woo, Kim Hyunjung
Department of Physics, Sogang University, Seoul 121-742, Republic of Korea.
Ultramicroscopy. 2008 Sep;108(10):1315-8. doi: 10.1016/j.ultramic.2008.04.086. Epub 2008 May 16.
Highly efficient organic light-emitting devices (OLEDs) have been realized by insertion of a thin insulating lithium fluoride (LiF) layer between aluminum (Al) cathode and an electron transport layer, tris-(8-hydroxyquinoline) aluminum (Alq(3)). In this paper, we study the surface morphology of LiF on Alq(3) by synchrotron X-ray scattering and atomic force microscopy (AFM) as a function of thickness of LiF. We also study the interdiffusion of LiF into Al cathode as well as into Alq(3) layer as a function of temperature. Initially, LiF molecules are distributed randomly as clusters on the Alq(3) layer and then gradually form a layer as increasing LiF thickness. The interdiffusion of LiF into Al occurs more actively than into Alq(3) in annealing process. LiF on Alq(3) induces the ordering of Al to (111) direction strongly with increasing LiF thickness.
通过在铝（Al）阴极和电子传输层三（8 - 羟基喹啉）铝（Alq₃）之间插入一层薄的绝缘氟化锂（LiF）层，实现了高效有机发光器件（OLED）。在本文中，我们通过同步加速器X射线散射和原子力显微镜（AFM）研究了LiF在Alq₃上的表面形态随LiF厚度的变化。我们还研究了LiF在不同温度下向Al阴极以及Alq₃层中的相互扩散情况。最初，LiF分子以团簇形式随机分布在Alq₃层上，然后随着LiF厚度的增加逐渐形成一层。在退火过程中，LiF向Al中的相互扩散比向Alq₃中的更为活跃。随着LiF厚度的增加，Alq₃上的LiF强烈诱导Al向（111）方向有序排列。
