Status and Prospects of AlN Templates on Sapphire for Ultraviolet Light-Emitting Diodes

S. Hagedorna, S. Waldea, A. Knauera, N. Susilob, D. Pacaka,b, L. Cancellarac, C. Netzela, A. Mogilatenkoa, C. Hartmannc, T. Wernickeb, M. Kneissla,b, and M. Weyersa

Published in:

phys. stat. sol. (a), vol. 217, no. 14, Special Issue: Ultraviolet Materials and Devices, pp. 1901022, <nobr>DOI: 10.1002/pssa.201901022</nobr> (2020).

Copyright © 2020 The Authors. Published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.

Abstract:

Herein, the scope is to provide an overview on the current status of AlN/sapphire templates for ultraviolet B (UVB) and ultraviolet C (UVC) light-emitting diodes (LEDs) with focus on the work done previously. Furthermore, approaches to improve the properties of such AlN/sapphire templates by the combination of high-temperature annealing (HTA) and patterned AlN/sapphire interfaces are discussed. While the beneficial effect of HTA is demonstrated for UVC LEDs, the growth of relaxed AlGaN buffer layers on HTA AlN is a challenge. To achieve relaxed AlGaN with a low dislocation density, the applicability of HTA for AlGaN is investigated.

a Ferdinand-Braun-Institut, Leibniz-Institut für Höchstfrequenztechnik, Gustav-Kirchhoff-Str. 4, 12489 Berlin, Germany
b Institute of Solid State Physics, Technical University Berlin, Hardenbergstr. 36, 10623 Berlin, Germany
c Leibniz Institute for Crystal Growth, Max-Born-Str. 2, 12489 Berlin, Germany

Keywords:

AlGaN, AlN, epitaxial lateral overgrowths, high-temperature annealing, nanopatterned sapphires, ultraviolet light-emitting diodes