Development of nano-electroluminescent devices by self-organization

该研究项目的目的是形成高发射微图案有机发光二极管。微图案的制备方法是通过稀溶液的脱湿机制使孔输运材料的微液滴自组织。微图被用来控制有机导体的取向，从而增加微图的发光。得到以下结果：1.稀溶液浇铸导致非晶态微滴的形成。热退火使有机材料结晶。晶体形态可以通过退火温度和预退火超声步骤来控制。可以制备单晶、多晶和晶体纤维。用低功功能金属或配合物包覆可改善电荷注入层。新合成的芳胺或三嗪衍生物可分别作为空穴导体和电子导体。其中一些化合物在热退火后还形成了定向微晶体。采用高导热衬底，并将电极尺寸减小到几μm.5，可获得超过10,000 A/cm^2的极高电荷密度。采用脱湿法对空穴导体进行微晶化，并对电子导体和顶电极进行真空沉积制备有机发光二极管。光学显微镜显示，只有脱湿孔导体才会发光。从而制备出微尺寸的发光点。对脱湿空穴导体进行退火处理，形成微尺寸的盘状聚集体，发光强度提高4倍。

The aim of the research project was the formation of highly emitting micropatterned organic light emitting diodes. The fabrication method for the micropatterns was the self-organization of micro-sized droplets of hole transport materials via a dewetting mechanism from dilute solution. The micropatterns were used to control the orientation of the organic conductors and thus increasing the luminescence of the micropatterns.The following results were obtained :1.casting from dilute solution led to the formation of amorphous microdroplets. Thermal annealing led to the crystallization of the organic material. Crystal morphology could be controlled by the annealing temperatare and by a pre-annealing ultrasonication step. Single crystal, polycrystrals as well as crystal fibers could be prepared.2.The charge injection layer could be improved by coating with low work function metals or complexes.3.Newly synthesized arylamines or triazine derivatives could be used as hole and electron conductors, respectively. Some of those compounds also formed oriented microcrystals upon thermal annealing.4.Extremely high charge densities of more than 10,000 A/cm^2 could be obtained by using substrates with high thermal conductivity and by reducing the electrode size to a few μm.5.Hole conductors were micropatterned via dewetting, and OLEDs were produced by vacuum deposition of electron conductors and top electrodes. Optical microscopy was used to show that only the dewetted hole conductors emitted light. Thus micronsized light emitting spots could be prepared. Annealing of the dewetted hole conductors led to the formation of micronsized disk-shaped aggregates that showed a 4 fold increase in luminescence.