Collaborative German project to deliver power UV LEDs by 2020
As well as replacing conventional UV light sources, which often contain toxic mercury, in areas such as production, disinfection, the environment, life sciences and medicine, the UV LEDs are also likely to open up new areas of application.
As part of “Advanced UV for Life”, a consortium of research institutes and companies funded under the federal “Zwanzig20” program, “UV Power” project coordinator Osram Opto Semiconductors is working with four partners, the Ferdinand-Braun-Institut, Leibniz-Institut für Höchstfrequenztechnik (FBH), the Technical University of Berlin, LayTec AG and UVphototonics NT GmbH.
Prototype LEDs and the technology for producing high-power LEDs for the UVB and UVC spectrums are being built using the aluminium gallium nitride (AlGaN) material system and results will be presented by 2020 when the project comes to fruition.
“The various tasks have been distributed among the partners on the basis of their strengths – everything from the production of structured sapphire substrates, epitaxy and chip processing to packaging and analytics”, said Dr. Hans-Jürgen Lugauer, Head of UV Development at Osram Opto Semiconductors. To speed up development and make efficient use of resources, the partners are splitting their work into different wavelength ranges.
In addition to coordinating the entire project, Osram Opto Semiconductors is taking on the wavelength range of 270 to 290nm.
In epitaxy, the Ferdinand-Braun-Institut is covering the adjacent wavelengths in the UVB range between 290 and 310nm and processing the epitaxial wafers into UV chips.
The Technical University of Berlin is focusing on the wavelength range of 250 to 270nm, applying its expertise in material analysis for AIGaN materials and AIGaN LEDs. TU Berlin also has extensive specialized equipment for UV analysis.
LayTec AG is developing tailor-made techniques for controlling the epitaxy and plasma etching systems.
FBH spin-off UVphotonics NT GmbH is the interface to users and is responsible for optimizing the chip design, for achieving high currents and for efficient cooling. The company is also handling the statistical collection and analysis of process data from the entire production chain and making this data available to the project partners for optimizing the production process.
The important subjects of assembly technology and the effects of aging will be investigated by FBH, TUB and UVphotonics in further projects as part of the consortium. The optical outputs of the new LEDs are expected to be greater than 120mW at 300 ± 10nm, 140mW at 280 ± 10nm and 80mW at 260 ± 10nm. The research group is also working on making significant improvements to the aging behaviour of the LEDs so they can be operated longer and more economically.
Advanced UV for Life – www.advanced-uv.de