Organic semiconductor heterojunction charge generation layer and its application in tandem organic light-emitting diodes

Tandem organic light-emitting diodes (OLEDs) have attracted a great deal of attention from researchers because of their high luminance, efficiency and stability. This paper summarizes past advances in the study of tandem OLEDs. Then, we present a bilayer organic semiconductor heterojunction charge generation layer made of p- and n-type organic semiconductors. A low operational voltage, high power efficiency tandem OLED was fabricated using this charge generation layer as a connecting unit. We also analyze the physical mechanisms that guide the operation of the device, and discuss methods for reducing the voltage and enhancing the power efficiency. Our design concept provides a template for the fabrication of high performance tandem OLEDs. Finally, we discuss the future of tandem OLED technologies.