【摘要】 通过比较三种用不同缓冲层材料(TiO2、Alq3和PBD)修饰ITO的有机电致发光器件和没有缓冲层修饰的器件发现,TiO2材料修饰的器件启亮电压最低,效率最高;Alq3修饰的器件启亮电压次之;PBD材料修饰的器件启亮电压最高,效率最低。TiO2的最优化厚度比Alq3和PBD的最优化厚度大,因此对于ITO表面的平整作用也较强。三种材料HOMO能级也不一样,TiO2材料的HOMO能级最高,因此三个材料中TiO2对于空穴的阻挡作用最大,通过隧穿作用穿过缓冲层材料PBD的空穴数就小于缓冲层材料Alq3和PBD,TiO2修饰的器件的载流子的平衡程度就高于Alq3和PBD修饰的器件,从而效率也高于Alq3和PBD修饰的器件。更多还原

【Abstract】 By comparing with the OLEDs with different buffer layers (TiO2, Alq3 and PBD), we find that the device with the TiO2 buffer layer shows the highest current efficiency and lowest operating voltage at the same current density.Because the optimal density of TiO2 is thickest than that of the Alq3 and PBD, so the TiO2 shows the smoothest effect on ITO. The hole-transporting mechanism in the organic material and inorganic material is different. In the inorganic material, the holes have the better transportation. The HOMO of TiO2 is higher than that of Alq3 and PBD.TiO2 can block more hole injecting which results in better carrier balance in the emitting layer. So the device with TiO2 buffer layer shows the highest current efficiency.更多还原