The chemical and morphological structures of the
surface and interface of organic electroluminescent
devices were evaluated using surface analysis techniques.
The effect of surface polarity of the substrate with
regard to the morphology of an overlying hole-transport
material was investigated by atomic force microscopy,
decomposition of the light-emitting material during
depositing cathode material was investigated by x-ray
photoelectron spectroscopy and time-of-flight secondary
ion mass spectro-metry, and the growth mechanism of
dark spots in devices was investigated based on the
mass spectrometry results. It was confirmed that these
analytical methods are useful for solving problems
related to the development of EL devices.
有機EL素子における表面・界面の化学構造または形態を,種々の表面分析技術により評価を試みた。正孔輸送層の形態に及ぼす基板の極性の影響を原子間力顕微鏡
(AFM) により,発光層と陰極との界面における発光材料の化学構造をX線光電子分光 (XPS) と飛行時間型二次イオン質量分析
(TOF-SIMS) により,素子の駆動により生成するダークスポットの生成メカニズムをTOF-SIMSによりそれぞれ調べた。その結果,これらの分析技術が素子の開発の各段階における諸問題の解決に有効であることが確認できた。