Researchers report breakthrough for very fast switching LEDs

In an experimental setup, researchers at Duke University have succeeded in making fluorescent molecules emit photons a factor of a thousand faster than regular LEDs. The technology can be used for quantum cryptography and optical communication.

The scientists, who work in the ‘plasmonics’ field, constructed a silver nanocube with sides of 75nm. The nanocube rested over a thin layer of gold during the study, EurekAlert reports. Experiments showed that fluorescent molecules trapped between the nanocube and the gold surface, in a space only 20 atoms wide, emit a much greater number of photons than normal LEDs: with current LED technology, atoms emit photons about 10 million times per second, but the Duke University researchers claim they can increase this speed by a factor of a thousand.

In a next step, the scientists want to examine whether it is possible to place the molecules more precisely under the nanocube in an ordered pattern. This could increase the ‘switching speed’ even further.

According to the scientists, their research still has rough edges, but in the long run it will make very fast switching LEDs possible. These could, for example, be used for optical communication via, for example, fiber optics. In the longer term, the technology could also be used for quantum cryptography.

The research results are described in the scientific journal Nature Photonics.