Boosting Organic Light-Emitting Diodes Technology Using Thermally Activated Delayed Fluorescent Emitters: A Review

Organic thermally activated delayed fluorescence (TADF) materials have become a focal point of research in the field of organic electronics due to their natural capacity to achieve 100% exciton utilization efficiency in organic light-emitting diodes (OLEDs) without the aid of noble metals. The combination of high efficiency seen in phosphorescent materials coupled with the straightforward synthesis and robust stability characteristic of fluorescent materials positions TADF as a compelling option for OLEDs, although their commercialization is at an early stage. A review of the current state of TADF emitters is timely and underscores the key challenges that must be overcome toward the development of a long operational time and high-efficiency TADF-based electroluminescent application in the future. In this paper, TADF materials are discussed and summarized by dividing into blue, green–yellow, and orange–red OLEDs according to the specific color of the devices. Molecular structure modification and its effect on the optoelectronic properties and device performance are discussed in detail to reveal the structure–property relationship. Importantly, the strategic protocol to enhance the device efficiency and operational stability is also presented, which provides future prospects for real-world applications.