Recent advances in thermally activated delayed fluorescence for white OLEDs applications

Thermally activated delayed fluorescence (TADF) materials, which can harvest all excitons without utilizing any noble metals to emit light, are becoming the key cornerstone for developing the next generation of organic light-emitting diode (OLED) devices. In recent years, TADF materials are attracting numerous attentions as a new surge of research focuses on both science and industry owing to their high efficiency, low power consumption, and low production cost attributes when applied to white OLEDs. The design and application of TADF in WOLED devices have also experienced the rapid development in fundamental science and industrial technology perspectives. In the present review, the specific reverse intersystem crossing mechanism and evolution of TADF is outlined firstly, and then the latest research progress of TADF-WOLEDs is summarized and discussed. TADF/conventional fluorescence, TADF/phosphorescence, all TADF and TADF exciplex-based WOLEDs are categorized and elaborated in terms of the device structure, working mechanism, efficiency, color-rendering index, etc. Finally, we conclude with the future challenges and opportunities in high-quality TADF devices and application area.