Blue fluorescence from the ligand and yellow phosphorescence from the iridium complex: High-efficiency wet-processed white organic light-emitting device

We synthesized four carbazole modified blue-emitting fluorescent ligands. These ligands coordinated with Ir3+ and four yellow-emitting phosphorescent complexes were obtained. A high-efficiency (current efficiency 20.6 cd/A) yellow electrophosphorescence device was wet-fabricated using the complex as a guest. The ligands can harvest and transfer energy to the complexes and a high efficiency (∼18 cd/A) white-light emitting device (CIE 0.31, 0.39) was obtained using the ligand as the blue-fluorescence emitter and the complex as the yellow-phosphorescence emitter. Therefore, the ligand can be a coordinator, an emitter and partly, a host. This is beneficial to device efficiency and saving cost for large-scale manufacturing.

Graphical abstractBlue-emitting fluorescent ligands and yellow-emitting phosphorescent iridium complexes were synthesized. The ligands can harvest and transfer energy to the complexes and therefore they can be a coordinator, an emitter and a host. The two materials are combined in a single layer of an OLED device to produce high-efficiency white-lighting.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Four blue-emitting fluorescent ligands were synthesized. ► Four yellow-emitting phosphorescent iridium complexes were synthesized. ► The ligands harvest/transfer energy to complexes, functioning as a coordinator/emitter/host. ► The ligands and the complexes are combined to produce white-lighting. ► Efficiency was improved, while saving cost for large scale manufacturing OLEDs.