The Study of Separately Doped Characteristics of Red Organic Light Emitting Diodes

Autor: Chuan-Yi Yang, 楊川毅
Rok vydání: 2004
Druh dokumentu: 學位論文 ; thesis
Popis: 92
This research is composed of several major parts. First of all, hole transport layer materials and other parameters are changed to obtain the optimum structure, then the concentration of red dopant DCJT is considered. Besides, we studied the luminance characteristics of ultra thin and extremely similar to quantum well doped structured. As far as hole transport layer material is concerned, the luminance of NPB-use device is about 10 times more than that of TPD-use device. In the part of doping-thickness-tuning, we set the concentration of DCJT 25%. When thickness of red doping layer is 10 nm, the luminance characteristics of corresponding device is better. About doping-concentration-tuning, the thickness of DCJT doping layer is fixed to 20 nm, and then the concentration of DCJT in Alq3 is changed (1%-25%). The peak of Electro-Luminescence spectra varies from yellow light to red light is observed; According to the results of experiments, when the concentration of DCJT increased, it will decrease the luminance characteristics of the corresponding device. This phenomenon is called "Concentration Quenching." In the other hand, the device depicts pure red light, the CIE coordinates is extremely close to (0.65, 0.35). Last but not least, This part of study is the quantum-well-doping structure of OLED where red dopant dye DCJT is doped into the host emitting layer (Alq3) by ultra thin quantum well doping. The parameters in the quantum well layer, including its width, position, number and spacing between quantum wells, are changed to study their effects on electroluminescence characteristics. It is found that both ultra thin double doped structure and C6-DCJT dual doped system can efficiently increase the luminance and efficiency of OLED device.
Databáze: Networked Digital Library of Theses & Dissertations
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