 Organic light-emitting diodes, OLEDs, are widely used in displays, lighting, and other applications due to their high efficiency and low power consumption. However, the electron behavior in these devices has not been thoroughly explored, making it difficult to optimize their performance. In this study, researchers examined the energy levels of blue OLEDs and how they affect the device's characteristics. They found that the energy level between the cathode and the emitting layer, e-mail, plays a key role in determining the operating voltage of the device. When a superbase was used as the electron injection layer, the energy level between the cathode and the e-mail was reduced, resulting in a lower operating voltage and better performance. This study provides valuable insight into optimizing the performance of blue OLEDs, which could lead to improved display and lighting technologies. This article was authored by Tsubasa Sasaki, Taku Ono, Takahisa Shimizu, and others.