Chinese chemists have discovered a soluble and simple-to-make iridium complex that boosts the efficiency of organic light-emitting diodes (OLEDs). This discovery could simplify the manufacture, and reduce the cost, of OLEDs for a wide range of future applications.
OLED screens have a number of advantages over conventional liquid crystal display (LCD) screens. Most importantly, light produced by OLEDs comes directly from the organic polymers that make up the display, rather than shining through coloured filters as in LCD screens.
This means that OLEDs do not require a backlight: they consume far less power and can be made significantly thinner. Materials scientists hope that OLEDs could even be directly printed onto surfaces, or used to make cheap fluorescent lighting.
But to efficiently harness light generated by the polymer, an ‘emissive layer’ of phosphorescent material is needed. This converts radiation that would otherwise be wasted into visible light, boosting clarity and brightness. The best materials for this purpose are complexes of iridium(III) with large cyclic ligands that grant stability, a rapid response time, and access to colours across the visible spectrum.
