缓冲层ZnPc对有机电致发光器件特性的影响

本文研究了酞菁锌(ZnPc)薄膜的表面形貌及ZnPc薄膜作为缓冲层对有机电致发光器件(OLEDs)光电特性的影响.对比两组样品的AFM图像,ZnPc薄膜相比于ITO薄膜,其表面的岛面积较大,薄膜表面更连续平整,基本上覆盖了ITO膜表面针孔,减少了表面的缺陷.另外,ZnPc薄膜的岛分布均匀有序.使用ZnPc作为缓冲层的器件性能明显好于未使用ZnPc修饰的器件,在7.42V的驱动电压下的最大发光亮度达到1.428kcd/m2,在4.3V电压驱动下时,最大光功率效率为1.411m/W;而未使用缓冲层的器件在8V的驱动电压下达到最大发光亮度达到1.212kcd/m2,在5.5V电压驱动下时,最大光功率效率为0.931m/W.

Effects of Zinc-phthalocyanine as the Buffer Layer on the Organic Light-emitting Devices

We have investigated the surface morphology of zinc-phthalocyanine(ZnPc) film and the effects of ZnPc as a buffer layer on the optical and electrical properties of organic light-emitting devices(OLEDs) in this paper.By comparing the morphology of the two samples measured by AFM images,the results indicate that the area of the island of ZnPc film is larger and has a smoother and more consecutive morphology than the sample of ITO film.The ZnPc film basically covers the surface pinholes and decreases the surface defect of the ITO film.Furthermore,the size of grain distribution was observed to be uniform and regular.It has been found the ZnPc-modified devices show better performance than that of the unmodified devices.The devices using ZnPc buffer layer have shown the largest luminance of 1.428kcd/m2 at a drive voltage of 7.42V and the best luminous efficiency of 1.41lm/W at 4.3V compared to the corresponding values of 1.212kcd/m2 at 8V and 0.93lm/W at 5.5V in unmodified devices.