An Electroluminescence Delay Time Model of Bilayer Organic Light-Emitting Diodes

Based on the mechanism of injection, transport and recombination of the charge carriers, we develop a model to calculate the delay time of electroluminescence （EL） from bilayer organic light emitting diodes. The effect of injection, transport and recombination processes on the EL delay time is discussed, and the relationship between the internal interface barrier and the recombination time is revealed. ＂]~he results show that the EL delay time is dominated by the recombination process at lower applied voltage and by the transport process at higher applied voltage. When the internal interface barrier varies from 0.15 eV to 0.3 eV, the recombination delay time increases rapidly~ while the internal interface barrier exceeds about 0.3eV~ the dependence of the recombination delay time on applied voltage is almost undiversified, which may serve as a guideline for designing of a high-speed EL response device.     

微腔有机发光器件中的电致发光光谱

设计了结构为Glass/DBR/ITO/TPD/Alq3/Ag的微腔有机发光器件。从理论上详细地研究了腔内各层结构对器件电致发光谱性能的影响。结果表明:随着腔长厚度的增加,器件的归一化电致发光谱强度不断减小;在可见光区,器件的EL谱随发光层厚度的增加出现振荡变化。空穴传输层和发光层的界面位置对器件电致发光谱的影响也很大。最后得到,在设计微腔时发光层厚度要尽量窄,并且中心发光区域应位于谐振腔中电场的峰值位置。