J. Rass^a,b, T. Kolbe^a,b, N. Lobo Ploch^a,b, T. Wernicke^b, F. Mehnke^b, C. Kuhn^b, J. Enslin^b, M. Guttmann^b, C. Reich^b, A. Mogilatenko^a, J. Glaab^a, C. Stoelmacker^a, M. Lapeyrade^a, S. Einfeldt^a, M. Weyers^a, M. Kneissl^a,b

Published in:

Proc. SPIE 9363, Photonics West, San Francisco, USA, Feb. 07-12, 93631K (2015).

Abstract:

UV light emitters in the UV-B spectral range between 280 nm and 320 nm are of great interest for applications such as phototherapy, gas sensing, plant growth lighting, and UV curing. In this paper we present high power UV-B LEDs grown by MOVPE on sapphire substrates. By optimizing the heterostructure design, growth parameters and processing technologies, significant progress was achieved with respect to internal efficiency, injection efficiency and light extraction. LED chips emitting at 310 nm with maximum output powers of up to 18mW have been realized. Lifetime measurements show approximately 20% decrease in emission power after 1,000 operating hours at 100mA and 5mW output power and less than 30% after 3,500 hours of operation, thus indicating an L₅₀ lifetime beyond 10,000 hours.

Keywords:

UV-LED, AlGaN, lifetime, UV-B, electroluminescence, MOVPE.

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