Directlink:

  1. Ferdinand-Braun-Institut
  2. Research
  3. Publications
  4. Low resistance distributed pol ...

Low resistance distributed polarization doped p-AlGaN layer for 265 nm LEDs operating at very high current densities

M. Grigoletto1,2, J. Höpfner1, M. Schilling1, T. Ehlermann1, L. Zeiler1, P. Sonka1, L. Sulmoni1, T. Wernicke1 and M. Kneissl1,2

Published in:

Semicond. Sci. Technol., vol. 41, no. 2, pp. 025019, doi:10.1088/1361-6641/ae44c5 (2026).

Abstract:

Ultraviolet-C light-emitting diodes (UVC-LEDs) with low resistance distributed polarization doped (DPD) p-type AlGaN layers are investigated. The UV-transparent DPD p-AlGaN layers provide high hole carrier densities in high aluminum mole fraction UVC-LEDs emitting near 265 nm. The influence of the DPD p-AlGaN layer thickness (50–320 nm) on the electrical and optical characteristics of UVC-LEDs is systematically evaluated. Despite the large variation of the DPD layer thickness, the voltages at 50 mA of the devices remained largely unchanged, demon- strating that the highly conductive p-type DPD layers do not significantly contribute to the series resistance. Nevertheless, UVC-LEDs with thinner DPD p-AlGaN layers exhibited higher output powers but also increased leakage currents. Capacitance–voltage (C–V) measurements show that the hole concentration increases from 6 × 1017 cm−3 to 4 × 1018 cm−3 with decreasing p-AlGaN DPD thickness from 320 nm to 50 nm consistent with simulation results. Under pulsed operation, UVC-LEDs were able to operate at very high current densities of up to 90 kA cm−2 without break- ing down. The findings of this study establish DPD p-AlGaN layers as a promising approach for high-performance UVC-LEDs, laser diodes and electronic devices.

1 Institute for Physics and Astronomy, Technische Universität Berlin, Hardenbergstrasse 36, Berlin 10623, Germany
2 Ferdinand-Braun-Institut (FBH), Gustav-Kirchhoff-Strasse 4, 12489 Berlin, Germany

Keywords:

electroluminescence spectroscopy, aluminum gallium nitride, ultra violet light emitting diodes, doping

© 2026 The Author(s). Published by IOP Publishing Ltd
Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.

Full version in pdf-format.