Improved injection efficiency in 290nm light emitting diodes with Al(Ga)N electron blocking heterostructure

T. Kolbe1, F. Mehnke1, M. Guttmann1, C. Kuhn1, J. Rass1, T. Wernicke1, and M. Kneissl1,2

Published in:

Appl. Phys. Lett., vol. 103, no. 031109 (2013).

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Abstract:

The effect of different Al(Ga)N electron blocking heterostructures (EBH) on the emission spectra and light output power of 290 nm light emitting diodes (LEDs) has been investigated. The carrier injection and internal quantum efficiency of the LEDs is simulated and compared to electroluminescence measurements. The highest light output power has been found for LEDs with an Mg-doped AlN/Al0.7Ga0.3N EBH with an AlN layer thickness >3 nm. The output power of these LEDs was 8.5- times higher compared to LEDs without EBH. This effect is attributed to an improved carrier injection and confinement which prevents electron leakage into the p-doped region of the LED with a simultaneously enhanced 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-Straße 4, 12489 Berlin, Germany

Keywords:

aluminium compounds, electron emission, gallium compounds, III-V semiconductors, light emitting diodes, magnesium, semiconductor heterojunctions, wide band gap semiconductors.