Yellow Phosphorescent Electrogenerated Chemiluminescence Cell Based on a Cyclometalated Iridium Complex with a Redox Mediator

Abstract

We demonstrated a bright yellow phosphorescent electrogenerated chemiluminescence (ECL) cell with a maximum luminance of over 100 cd m⁻² and a maximum current efficiency of 2.84 cd A⁻¹ by adding a redox mediator to the iridium complex solution, which are both among the highest values ever reported for the iridium complex-based ECL cells. Here, bis(2-phenylbenzothiazolato)(acetylacetonate)iridium(III) (Ir(BT)₂(acac)) was used as a luminescent material, while 4,5-bis(carbazol-9-yl)-1,2-dicyanobenzene (2CzPN) was used as the mediator. The working mechanism for the developed cell was discussed based on the electrochemical and photophysical properties of the employed materials.