Multi-colour LEDs

A team of University of California scientists at Los Alamos National Laboratory have developed the first completely inorganic, multi-colour light-emitting diodes (LEDs) based on colloidal quantum dots encapsulated in a gallium nitride (GaN) semiconductor.

The work is said to represent a new “hybrid” approach to the development of solid-state lighting, which offers the advantages of reduced operating expenses, lower energy consumption and more reliable performance.

In research published in the current issue of the scientific journal Nano Letters, the team reports on the first successful demonstration of electroluminescence from an all-inorganic, nanocrystal-based architecture where semiconductor nanocrystals are incorporated into a p-n junction formed from semiconducting GaN injection layers. The new LEDs utilise a novel type of colour-selectable nanoemitters, colloidal quantum dots, and makes use of emerging GaN manufacturing technologies.

According to Dr. Victor Klimov, who leads the nanocrystal-LED research effort, “numerous technologies could benefit from energy efficient, colour-selectable solid-state lighting sources ranging from automotive and aircraft instrument displays to traffic signals and computer displays.