Role of substrate quality on the performance of semipolar (1122) InGaN light-emitting diodes
D.V. Dinh1, B. Corbett1, P.J. Parbrook1,2, I.L. Koslow3, M. Rychetsky3, M. Guttmann3, T. Wernicke3, M. Kneissl3, C. Mounir4, U. Schwarz5, J. Glaab6, C. Netzel6, F. Brunner6, and M. Weyers6
Published in:
J. Appl. Phys., vol. 120, no. 13, pp. 135701 (2016).
Abstract:
We compare the optical properties and device performance of unpackaged InGaN/GaN multiple-quantum-well light-emitting diodes (LEDs) emitting at ∼430 nm grown simultaneously on a high-cost small-size bulk semipolar (1122) GaN substrate (Bulk-GaN) and a low-cost large-size (1122) GaN template created on patterned (1012) r-plane sapphire substrate (PSS-GaN). The Bulk-GaN substrate has the threading dislocation density (TDD) of ∼105 cm-2 - 106 cm-2 and basal-plane stacking fault (BSF) density of 0 cm-1, while the PSS-GaN substrate has the TDD of ∼2×108 cm-2 and BSF density of ∼1×103 cm-1. Despite an enhanced light extraction efficiency, the LED grown on PSS-GaN has two-times lower internal quantum efficiency than the LED grown on Bulk-GaN as determined by photoluminescence measurements. The LED grown on PSS-GaN substrate also has about two-times lower output power compared to the LED grown on Bulk-GaN substrate. This lower output power was attributed to the higher TDD and BSF density.
1 Tyndall National Institute, University College Cork, Lee Maltings, Dyke Parade, Cork, Ireland
2 School of Engineering, University College Cork, Cork, Ireland
3 Institut für Festkörperphysik, Technische Universität Berlin, Hardenbergstraße 36, 10623 Berlin, Germany
4 Institut für Mikrosystemtechnik, Albert-Ludwigs-Universität Freiburg, Georges-Köhler-Allee 103, 79110 Freiburg, Germany
5 Institut für Physik, Technische Universität Chemnitz, Reichenhainer Straße 70, 09126 Chemnitz, Germany
6 Ferdinand-Braun-Institut, Leibniz-Institut für Höchstfrequenztechnik, Gustav-Kirchhoff-Strasse 4, 12489 Berlin, Germany
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