Using its latest thin-film technology, Osram Opto Semiconductors GmbH of Regensburg, Germany has developed a 1mm2 infrared LED chip prototype that has achieved what is claimed to be record efficiency of up to 72% at an operating current of 100mA.
This wall-plug efficiency (WPE, the ratio of radiated power to electrical input power) was measured at room temperature at a DC current up to 1A. At 930mW from an operating current of 1A, the light output power under laboratory conditions is 25% higher than that of any chips currently on the market, the firm claims.
Graphic: The 1mm2 IR chip has wall-plug efficiency of up to 72% and a high external quantum efficiency (remaining around 65% up to 1A).
The prototype 1mm2 infrared chip also has a high external quantum efficiency (EQE) that remains around 65% for operating currents up to 1A. The 850nm wavelength suits infrared illumination applications, particularly for surveillance tasks and use with CCTV cameras. There are also potential safety applications in the automotive sector, such as pre-crash sensors and illumination sources for night-vision systems.
“The way in which the efficiency and brightness have been increased can be transferred from 850nm to other wavelengths,” says Markus Bröll, project manager for the development of IRED chips. “This means that it will be possible to create highly energy-efficient solutions for infrared lighting in the future.” Fewer components will be needed in multi-chip applications, he adds, saving both money and energy.
The results of the development work are now being implemented stage by stage. The new chip is expected to go into series production by mid-2013. Future infrared LEDs can be made even more energy efficient, it is expected.
