Abstract
The development of iridium complex-based organic light-emitting diodes (OLEDs) is undoubtedly a highly relevant area of modern optoelectronics due to their outstanding electroluminescent performance and nearly 100% internal quantum efficiency. The photophysical properties of these systems are largely governed by the nature of the coordinated ligands, making the design and synthesis of novel ligand architectures an important research objective. In particular, the introduction of an ortho-carborane moiety enables precise tuning of the electronic and steric properties of the ligand while improving the thermal and chemical stability of the resulting complexes and suppressing concentration quenching. Consequently, carborane-containing iridium complexes represent promising emitters for the development of highly efficient OLED devices. In this work, cationic iridium(III) complexes were synthesized via the reaction of ortho-carboranyl bipyridine ligand systems with dichlorotetrakis(2-phenylpyridine)diiridium(III). Based on one of the synthesized complexes, a prototype yellow OLED was fabricated, exhibiting a maximum luminance of 3500 cd/m².