Dresden 2011 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 85: Poster Session II

HL 85.130: Poster

Donnerstag, 17. März 2011, 18:00–21:00, P4

Study of transport processes in AlGaInN-based light-emitting diodes — •Bastian Galler, Ansgar Laubsch, Andreas Wojcik, Hans-Jürgen Lugauer, Alvaro Gomez-Iglesias, Matthias Sabathil, and Berthold Hahn — OSRAM Opto Semiconductors GmbH, Leibnizstraße 4, 93055 Regensburg, Germany

Several experiments investigating the efficiency droop in AlGaInN-based light-emitting diodes (LEDs) point to a loss mechanism resulting from a too high carrier density in the active region causing the decreasing efficiency at high currents [1,2]. Therefore, it is desirable to spread carriers over a larger active volume to achieve good efficiency values at high current densities. As this is difficult to achieve in GaN-based LEDs, a detailed understanding of the transport processes governing the carrier distribution in GaN/InGaN multi-quantum-wells (MQWs) is crucial for further brightness improvements. We study colour-coded LEDs featuring one QW emitting at a longer wavelength to analyze the carrier distribution experimentally. Although the absolute emission from such a high-indium QW is increased due to its more favourable energetic level, valuable insight can be gained analyzing the fraction of the colour-coded emission as a function of temperature and current density.

[1] Y.C. Shen et al., Appl. Phys. Lett. 91, 141101 (2007). [2] A. Laubsch et al., IEEE Transactions on Electron Devices, 7, No. 1 (2010).