The Ferdinand braun-institut and its subsidiary, UVphotonics NT, will present their latest UV leds at the 2018 international congress on UV leds and applications in Berlin on April 22, solstice 25.

Along with improved efficiency and output power, combined with small sizes, UV leds are used in a growing number of applications, including water, air and surface sterilization and the curing of synthetic materials. UV leds switch and adjust light quickly, and the heat is efficiently distributed through the heat sink. Unlike mercury lamps, UV leds are made of non-toxic materials and their wavelength can be adjusted in a wide range of spectrum.

They discovered a degradation mechanism in the development process: in the first few hours of operation, the electrical migration of hydrogen in the uv-b LED structure would occur, which would accompany the optical power reduction of the device.

The L50 UV-B LED with a life of 8,000 hours can be built by design adjustment. The optimization of the device further improves the reliability of the LED, and the L50 life is expected to be significantly extended. In addition, the output power at 350mA can be increased to 30mW.

The uv-led lighting system shown in the figure has three different wavelengths. Their brightness and irradiation intensity can be individually adjusted to determine the optimal irradiation for plant secondary metabolites with diverse structures.

At the conference, the FBH scientists will also show a compact diode laser light source for the deep uv spectrum, with a emission wavelength of 222 nm, in an area where leds are difficult to reach. The device converts light from a high power diode laser based on gallium nitride into the ultraviolet spectrum range through frequency multiplication (one-way) and may be miniaturized. Wavelength stable narrow-band light sources are particularly suitable for spectral applications, such as absorption spectrum and Raman spectrum, for medical diagnosis and substance analysis.