Osram’s red LED tops 100 lm/W output
Germany-based LED manufacturer Osram Opto Semiconductors says that it has made a red surface-emitting LED with a record high luminance.
At 100 lm/W, the efficiency of the device is also thought to be a record for the 618 nm emission wavelength.
The LED, which emits more than 12 lm through a 300x300 µm surface at a 70 mA drive current, incorporates Osram’s thin-film technology.
Osram told Compoundsemiconductor.net that technology used in the latest device will be applied in the company’s second generation of commercial thin-film devices, which are planned for launch as fully-qualified products in 2005.
The brightness of Osram’s LED is very close to another efficient device made by the company’s US-based rival Lumileds. The Lumileds device operates at a slightly shorter wavelength than Osram’s, to which the human eye is slightly more sensitive.
The Lumileds LED features a 1x1 mm chip in the shape of an inverted pyramid, using all sides of the pyramid to enhance light extraction. Osram says that this means the approach results in a relatively low luminance and cannot be applied to smaller dies.
Osram says that its LED will be suitable for any high-brightness applications, such as automotive backlights and traffic lights. The first generation of thin-film products is currently being used in a head-up display for the BMW 5 Series, for example (see related story).
The next step, says Osram, will be to establish the second generation technology as a platform for all AlGaInP colors and chip sizes. Development work will focus on further improving efficiency and luminance.
Osram added that InGaN-based blue- and white-emitting devices based on the thin-film technology will be launched within the next few weeks.