High Efficiency in a Solution-Processed Thermally Activated Delayed-Fluorescence Device Using a Delayed-Fluorescence Emitting Material with Improved Solubility

摘要

Solution-processed organic light-emitting diodes (OLEDs) have attracted great attention as a device for application in large-size OLEDs because of simple fabrication process and easy scalability of the solution process. However, the device performances of the solution-processed OLEDs are still inferior to those of vacuum-deposited OLEDs and further improvement of the device performances of solution-processed OLEDs is required. There have been many papers reporting improved device performances in solution-processed OLEDs and most research has been directed to enhancing the quantum efficiency using soluble triplet host and phosphorescent emitting materials. In most cases, a small-molecule host and dopant materials for vacuum-deposited phosphorescent organic light-emitting diodes were modified or used without modification for application in solution-processed devices, which improved the quantum efficiency of the solution-processed phosphorescent OLEDs. High quantum efficiency close to 20% was reported in red, green and blue phosphorescent OLEDs.