Milliwatt power 233 nm AlGaN-based deep UV-LEDs on sapphire substrates

N. Lobo-Ploch1,2, F. Mehnke3, L. Sulmoni3, H.K. Cho1, M. Guttmann3, J. Glaab1, K. Hilbrich1, T. Wernicke3, S. Einfeldt1, and M. Kneissl1,3

Published in:

Appl. Phys. Lett., vol. 117, no. 11, pp. 111102, DOI: 10.1063/5.0015263 (2020).

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Deep UV-LEDs (DUV-LEDs) emitting at 233 nm with an emission power of (1.9±0.3) mW and an external quantum efficiency of (0.36±0.07) % at 100 mA are presented. The entire DUV-LED process chain was optimized including the reduction of the dislocation density using epitaxially laterally overgrown AlN/sapphire substrates, development of vanadium-based low resistance n-metal contacts, and employment of high thermally conductive AlN packages. Estimated device lifetimes above 1500 h are achieved after a burn-in of 100 h. With the integration of a UV-transparent lens, a strong narrowing of the far-field pattern was achieved with a radiant intensity of 3 mW/sr measured at 20 mA.

1 Ferdinand-Braun-Institut, Leibniz-Institut für Höchstfrequenztechnik, Gustav-Kirchhoff-Str. 4, 12489 Berlin, Germany
2 UVphotonics NT GmbH, Gustav-Kirchhoff-Str. 4, 12489 Berlin, Germany
3 Institute of Solid State Physics, Technische Universität Berlin, Hardenbergstr. 36, 10623 Berlin, Germany


Quantum efficiency, Light emitting diodes, I-V characteristics, Flip chip, Semiconductor device fabrication