Brighter future

A new type of light-emitting diode (LED) with significantly improved lighting performance and energy efficiency has been developed by researchers at Rensselaer Polytechnic Institute.

The new polarisation-matched LED, developed in collaboration with Samsung Electro-Mechanics, exhibits an 18 per cent increase in light output and a 22 per cent increase in wall-plug efficiency, which essentially measures the amount of electricity the LED converts into light.

The device also achieves a notable reduction in ‘efficiency droop’; this is a well-known phenomenon that causes LEDs to be most efficient when receiving low-density electric currents, but then to lose efficiency as higher-density currents are fed into the device. The cause of this droop is not yet fully understood, but studies have shown that electron leakage is likely to be a large part of the problem.

‘Droop is under the spotlight since today’s high-brightness LEDs are operated at current densities far beyond where efficiency peaks,’ said Rensselaer project leader Prof E Fred Schubert.