MORPHOLOGY CONTROL OF ORGANIC THIN FILMS BY ION-BEAM-ASSISTED DEPOSITION AND THEIR APPLICATION TO E.L.DIODE

本研究的主要成果如下：1.提出了一种基于考夫曼型离子源的离子束辅助沉积有机材料的新方法.与传统的蒸发法相比，该方法制备的8-羟基喹啉铝（Alq_3）薄膜的形貌、结晶度和堆积密度都有很大的改善.采用氦离子束，在束流为50 ~ 120 nA/cm^2，束流能量为100 eV的条件下，获得了高质量的Alq_3发光层.双层电致发光二极管在室温下发出绿色光。这种电致发光强度比用热淀积方法获得的电致发光二极管的电致发光强度大几倍。从低能离子束辐照对发光层的形貌、晶化或堆积密度的影响结果可以推测出电致发光强度的增强效应。蒸发的TPD膜也证实表现出高空穴传导。

The results of this scientific research are summarized as follows.1. A new method of the ion-beam-assisted deposition of organic materials using the Kaufman-type ion source was proposed.2. The morphology, crystallization and packing density of 8-hydroxyquinoline aluminum (Alq_3) films prepared by this method were confirmed to be greatly improved compared with that obtained with the conventional evaporation method.3. The high quality emitting layrs of Alq_3 were obtained in the range of the ion beam current between 50 nA/cm^2 and 120 nA/cm^2 for the ion beam energy of 100 eV using helium ion beams.4. The EL diode of double layr emitted green light at room temperature. This EL intensity was several times lager than that of EL diodes obtained with thermal deposition method. The enhancement effect of EL intensity may be suggested from the results that the morphology, crystallization or packing density of the emitting layrs have been progressed by low energy ion beam irradiation. The evaporated TPD films also confirmed to exhibit high hole conduction.