The Design and Progress of Organic Light-Emitting Diode

Abstract

Organic light emitting diode (OLED) is one of the main lighting devices and can be used as mobile phone screens, so its performance enhancement is worthy of an in-depth study. This paper discusses three types of devices with different light emitting principles in the history of OLED development in chronological order and their performances, as well as ways to enhance their external quantum efficiency (EQE). For fluorescent, phosphorescent and thermally activated delayed fluorescent (TADF) OLEDs, adding additional layers and doping are effective means of improving the performance. For fluorescent OLED, the EQE can be increased up to 11.5% by adding an efficiency enhancement layer and doping the emitting layer with a new blue dopant with a higher orientation coefficient. For phosphorescent OLED, a hole transport layer is utilized to block excitons within the FIrpic-doped emissive layer leading to an EQE of 16.7%. For TADF OLED, the soluble doped TADF OLEDs is helpful at improving the quantum efficiency up to 18.3%. This paper looks forward to the maturation of these strategies and their practical application, and the identification of more technologies that can enhance the performance of OLED devices to help make it more usable.