Study and improvement of the luminescent and degradation mechanism of organic electroluminescent devices

采用真空汽化法制备了ITO/TPD/Alq3/Mg结构的有机电致发光器件，并对其电致发光性能进行了研究。EL器件发出强绿光，ITO电极的极性穿过TPD，穿透Alq3，与Mg电极注入的电子在TPD/Alq3界面区重新结合。光通过电子空穴材料发射。获得蓝、绿、红灯。在本报告中，我们研究了薄膜制备条件对有机电致发光器件性能的影响。主要研究结果如下：(1) Alq3沉积速率高导致EL高。(2) TPD沉积速率对EL强度没有影响。(3)电子束蒸发比射频溅射提供了更好的ITO阳极。(4)功函数低的Mg导致了高EL。(5) ITO基板上的等离子体修饰降低了EL器件的驱动电压。(6) DCM和Coumarine的掺杂提高了EL器件的效率。(7)掺杂镓染料有一种新型发光器件。薄膜制备条件的优化和材料的选择是提高有机电致发光器件性能的重要因素。

Organic EL devices with a structure of ITO/TPD/Alq3/Mg were prepared by the vacuumevaporation method and their EL properties were investigated in order to improve them. The EL device emits strong green light with the polarity of the ITO electrode move through TPD,penetrate into Alq3 and recombine there with electrons which are injected from Mg electrode and arrive at the TPD/Alq3 interface region. Light is emitted through the electron-hole materials. Blue,green and red lights are obtained. In this report, we have investigated the effects of the conditions of film preparation on properties of the organic EL device. Main results obtained are as follows; (1) High deposition rate of Alq3 resulted in high EL. (2) The deposition rate of TPD did not affect the EL intensity. (3) Electron beam evaporation provided a better ITO anode than RF sputtering. (4) Mg which has a low work function resulted in high EL. (5) Plasmamodification on the ITO substrate lowers the driven voltage of EL devices. (6) Doping of DCM and Coumarine gives EL device a high efficiency. (7) Doping of squarylium dye has a new type EL device. It is important for the improvement of the organic EL devices to optimize the conditions of film preparation as well as to select materials.