What Colin Humphreys and his colleagues at Cambridge have come up with is a reliable way to deposit gallium nitride on much cheaper silicon wafers, which they estimate could cut production costs to a tenth of what they are at the moment.
At present these LEDs are made in machines similar to those used to make silicon chips, by depositing layers of gallium nitride on sapphire-based wafers.
Because the atomic lattice structure of gallium nitride is better matched to sapphire than it is to silicon, making LEDs on silicon without distortions has proved extremely tricky.
Gallium-nitride is manmade and not found in nature, and historically, LEDs are made by growing a gallium-nitride layer on top of a base material, which is typically sapphire or, more recently, silicon carbide.