8 December 2017
German-funded UV Power project working on LED replacements for conventional UV light sources
Since February, five research institutes and companies have been working on ‘UV Power’, a collaborative research project funded by the German Federal Ministry of Education and Research (BMBF) as part of ‘Advanced UV for Life’, a consortium of research institutes and companies being funded under Germany’s federal ‘Zwanzig20’ program. Prototype LEDs and the technology for producing high-power LEDs for the UVB and UVC spectrums on the basis of the aluminium gallium nitride (AlGaN) material system are scheduled to be presented by 2020.
The UV Power project is co-ordinated by Osram Opto Semiconductors GmbH of Regensburg, Germany working with four partners: the Ferdinand-Braun-Institut, Leibniz-Institut für Höchstfrequenztechnik (FBH), the Technical University of Berlin, LayTec AG, and UVphototonics NT GmbH.
The partners aim to develop new technology for high-power, mass-market UV LEDs spanning a wide variety of applications. The LEDs will eventually replace conventional UV light sources (which often contain toxic mercury) in areas such as production, disinfection, the environment, life sciences and medicine. UV LEDs are also likely to open up new areas of application.
The partners are therefore pooling their scientific expertise and making their highly specialized technical facilities and analysis methods available. Development of the high-power LEDs is taking place along the entire technology chain for LED production. “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,” says Dr Hans-Jürgen Lugauer, head of UV development at Osram Opto. “With our presence on the international market and our expertise in industrial manufacturing we are boosting the impact of the consortium considerably,” he adds.
To speed up development and make efficient use of resources, the partners are splitting their work into different wavelength ranges. In addition to co-ordinating the entire project, Osram Opto is taking on the wavelength range 270-290nm. In epitaxy, the FBH is covering the adjacent wavelengths in the 290-310nm UVB range and processing the epitaxial wafers into UV chips. Technical University of Berlin is focusing on the wavelength range 250-270nm, applying its expertise in material analysis for AlGaN materials and AlGaN LEDs. TU Berlin also has extensive specialized equipment for UV analysis. LayTec is developing tailor-made techniques for controlling the epitaxy and plasma etching systems. FBH spin-off UVphotonics is the interface to users, responsible for optimizing the chip design, for achieving high currents, and for efficient cooling. The firm 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 ageing 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 ageing behaviour of the LEDs so they can be operated for longer and more economically.