Korean researchers have developed a new blue nitride LED that uses 3D graphene foam as a transparent conductor for the p-contact. They say that the graphene foam reduced the forward voltage by 26% and increased the light output by 14%.
The researchers used commercial 3D graphene foam, produced on 3D copper foam using chemical vapor deposition. The graphene foam on copper was then spin-coated with PMMA and the copper etched away (using ammonium sulfate). The graphene foam was cut into a square and transferred to the p-type gallium nitride layer of a commercial blue LED.