Light-Emitting Dendrimers

Chemical structure of an iridium dendrimer. The core (green) controls the photophysical properties, the dendrons (blue) control the distance between neighbouring cores and so morphological properties, and finally the surface groups (red) control the solubility and environmental interaction of the material.

In collaboration with Prof. Paul Burn at the University of Queensland we are exploring a novel approach to light-emitting materials involving starburst or dendritic molecules. These highly branched molecules are self-similar, resembling for example snowflakes. They provide an elegant way of controlling properties such as colour and intermolecular interactions. We have used them to make red, green and blue light-emitting diodes, and to tune mobility and study its effect on device operation. Using these dendrimer materials we have reported the highest efficiency solution processable OLED devices in the world, at 15% external quantum efficiency. The unique properties of dendrimers have made them an attractive suite of materials to employ across a wide range of organic semiconducting systems, including solar cells and photodiodes.