基于MoO_(3)/ZnO无机电荷产生层的量子点电致发光器件

Quantum-dot Light-emitting Diodes Based on MoO_(3)/ZnO Inorganic Charge-generation Layer

氧化锌(ZnO)作为一种优异的电子传输材料,广泛应用于高性能量子点电致发光器件(QLED)中。然而,由于ZnO层较高的电荷传输速率,导致器件中过多的电子注入,使得器件内部的载流子不平衡,降低了器件的效率。此外,ZnO的易潮解性质使得其与电极之间的接触容易受到外界环境(水分和氧气)影响,从而影响器件的存储稳定性,这在倒置结构的QLED中尤为明显。为解决上述问题,我们利用MoO_(3)/ZnO作为电荷产生层(CGL)来制备倒置结构的QLED。这一结构改善了器件的载流子不平衡问题,使得器件的最大电流效率从12.8 cd/A提升到了15.7 cd/A。此外,CGL无需有电极注入电荷,而是通过电场的作用产生电荷,注入到发光层中,这降低了电极界面对器件性能的影响,从而大大提高了器件的稳定性。

Zinc oxide(ZnO)is commonly used in high-performance quantum dot light-emitting diodes(QLEDs)as electron-transport layers due to its excellent electrical properties.However,due to high electron mobility of the ZnO layer,excessive electrons are injected into the device,which leads to imbalanced charge carriers inside the devices and low efficiency.In addition,the contact between ZnO and the electrode is easily affected by the external environ⁃ment(water and oxygen),particularly for the inverted QLEDs,which dramatically affects the storage stability of de⁃vices.To solve the above problems,we use MoO_(3)/ZnO as charge-generation layer(CGL)to prepare inverted QLEDs.This structure reduces carrier imbalance and increases the maximum current efficiency of the device from 12.8 cd/A to 15.7 cd/A.In addition,the influence of cathodes on the device performance is highly reduced in the CGL based QLEDs because the electrons are generated in the CGL,rather than being injected from the cathode.As a result,the storage stability of devices is greatly improved.