有机白光器件中CdS薄层增加电子注入的研究

Research on Increasing Electron Injection in CdS Thin Layer of White Organic Light-emitting

摘要:

为了研究光电材料CdS在有机白光器件中增加电子注入的特性，将结构为ITO/NPB/Rubrene/NPB/DPVBi/Alq₃/LiF/Al的白光器件，不插入CdS薄层或将CdS薄层分别插入到NPB和ITO之间以及Alq₃和LiF之间或同时将CdS薄层插入到它们之间，制作了四个元器件。通过研究得出，在Alq₃和LiF之间插入CdS薄层的器件，在同等条件下性能较好。性能的改善来自于CdS薄层的引入使器件电子注入增加，激子形成的数量和比率也获得了相应的提高，从而提高了器件的亮度和效率。

Abstract:

In order to study the photoelectric characteristics of increasing the electron injection, white organic light-emitting diodes with the structure of ITO/NPB/Rubrene/NPB/DPVBi/Alq₃/LiF/Al were fabricated. Four devices with different inserting layer were fabricated as: for the first one, there is no insert of photoelectric material CdS; for the second one, CdS layer is inserted between NPB and ITO; for the third one, it is inserted between Alq₃and LiF and for the fourth one, it is inserted both of them. From the current density-voltage characteristics, it is noticed that the current density of WOLEDs is higher than the others through inserting CdS between Alq₃ and LiF under the same condition. Only the current density of the second device increases. The reason is that the CdS thin layer absorbs part of the short wavelength blue-light emission and increases the electron injection of the device, and also the number and ratio of excitions increase correspondingly, so the brightness and efficiency of the device are improved.