High-efficiency LED developments

Osram Opto Semiconductors has raised the efficiency of its high-performance red LED by 30% under laboratory conditions. This record-setting efficiency was achieved through optimisation of the chips. The improved LED is currently more efficient than any other diode that operates at the same wavelength.

Red LEDs are used in vehicle tail and brake lights, as well as for illuminating buildings and stages and, when used in combination with white LEDs, they produce a comfortable warm white light for illuminating interiors. The efficiency increase means the units now achieve a higher light output at the same level of power consumption. However, their application not only saves energy but also space, since fewer diodes can now produce the same brightness.

In developing the new chip, Osram engineers improved the material properties and output efficiency of their high-performance thin-film chips. The result is a prototype of a red Golden Dragon Plus LED that emits at a wavelength of 615 nm and delivers 119 lumens of light per watt at a current of 350 mA. Its high efficiency of 44% also reduces waste heat by nearly 50% as compared to previous LED versions. This, in turn, reduces the need for cooling, and also means that the designs can be made smaller.

The new technology is planned to be transferred into production as quickly as possible. In addition, the company plans to apply the new technology to yellow (590 nm) and hyper-red (645 nm) LEDs.