有机发光材料的电化学稳定性及其对器件稳定性的影响

有机发光器件（OLED）在平板显示和固体照明领域有着广阔的应用前景.过去的二十多年来,OLED的效率得到了大幅提升,但是器件的稳定性仍有待提高.在OLED器件中,通常认为载流子的传输涉及分子反复的氧化还原.因此,OLED材料的电化学性质是影响器件稳定性的重要因素.本文总结了近年来有关OLED材料电化学性质的研究进展,并重点探讨了材料的电化学稳定性与器件稳定性之间的关系.总结发现：（1）单极性材料的电化学不稳定性是导致器件衰减的本质原因之一;（2）双极性材料高度的电化学稳定性有助于提高器件的稳定性,但并不一定保证器件具有高稳定性;（3）有关材料分子结构的稳定性对器件稳定性的影响以及器件的本征衰变机制还有待深入研究.相信,对OLED发光材料稳定性和器件衰变机制的深入研究将有助于提高其他有机光电材料和器件的稳定性,从而推动有机电子学和相关产业的发展.

The electrochemical stability of organic materials and their influence on the operational stability of organic light-emitting devices

Organic light-emitting diodes （OLEDs） have drawn great attention because of their potential application in full-color displays and solid-state lighting. The efficiency of OLEDs has been significantly boosted over the last two decades; however, the device stability is still a challenge. As the charge-carrier transport in OLEDs is generally considered as a chain of redox processes between the neutral molecules and the corresponding radical ions, the electrochemical property of the materials should be an important factor associated with the operational stability of OLEDs. In this perspective, we reviewed the recent advances on the electrochemical property of OLEDs materials, focusing on revealing the correlation between the electrochemical properties of OLEDs materials and the operational stability of the corresponding devices. We try to summarize as follows： （1） The electrochemical instability of unipolar materials has been recognized as one of the intrinsic factors leading to the device degradation; （2） The high electrochemical stability of bipolar materials has proved to be conducive to significantly enhance the stability of the corresponding devices, but not guarantee the devices definitely with high stability; （3） The influence of the molecular stability on device stability, and the intrinsic degradations mechanism of OLEDs still remain to be further explored. It is expected that the in-depth knowledge of the materials stability and the degradation mechanisms of OLEDs can help to improve the stability of other organic optoelectronic materials and devices, thus promoting the development of organic electronics and related industries.