Efficient carrier-injection and electron-confinement in UV-B light-emitting diodes

T. Kolbe1,2, J. Stellmach1, F. Mehnke1, M.-A. Rothe1, V. Kueller2, A. Knauer2, S. Einfeldt2, T. Wernicke1, M. Weyers2, and M. Kneissl1,2

Published in:

phys. stat. sol. (a), vol. 213, no. 1, pp. 210-214 (2016).

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Abstract:

The effects of the aluminum content x and the magnesium doping concentration in the AlxGa1-xN:Mg electron blocking layer on the emission characteristics of ultraviolet lightemitting diodes has been investigated. The carrier injection in the light-emitting diodes is simulated and compared with electroluminescence measurements. The light output power depends strongly on the aluminum mole fraction x as well as on the magnesium supply in the vapor phase during the growth of the AlxGa1-xN:Mg electron blocking layer. The highest output power has been found for an aluminum content x of around 44% and an Mg/III-ratio of 3.0% for light-emitting diodes with an emission wavelength near 320 nm. This effect can be attributed to an improved carrier injection and confinement preventing electron leakage into the p-doped layers of the light-emitting diode and an effective hole injection into the active region.

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

Keywords:

electroluminescence, electron blocking layers, InAlGaN, light-emitting diodes, MOVPE.