摘要
Long lifetime and high efficiency are strongly desired for electronic devices. Encapsulation is especially required for organic light-emitting diodes (OLEDs) because they are extremely sensitive to the ambient moisture and oxygen. However, few studies had investigated their individual effects. We found in this study that even with a trace amount, oxygen showed drastically marked effects on both the short- and long-term properties of OLEDs, either typical or tandem. It is unprecedented to see that moisture did not compromise the device performance at least within the 20 ppm level. In contrary, the moisture helped alleviate the attack of oxygen via reducing its kinetic energy and collision probability striking on the aluminum surface. The findings suggest a more stringent oxygen control in fabrication and encapsulation to achieve an upmost device performance.