LEDs have the disadvantage that the devices are complex and multilayered and they require high-vacuum and high temperature techniques for their preparation. LEDs also need to be rigorously protected from exposure to air or water.
Recently, the researchers have designed new molecular components and strategies for the preparation of light-emitting electrochemical cells (LECs) with lifetimes exceeding 2500hrs. LECs are simpler devices than LEDs and comprise one layer of active material that can be solution-processed in ambient conditions.
So far LEC devices have had relatively short lifetimes which have precluded serious commercial investigation. The research teams have demonstrated that devices with lifetimes exceeding 2500hrs can now be prepared using molecular components stabilized by aromatic rings. The team has built metal complexes decorated with rings that arrange themselves to form a shell around the molecule. The supramolecular interactions make the complexes exceptionally stable while molecular tuning of the components allows a tuning of the color of LED lights emitted, bringing the goal of white-light emitting devices one step closer.