Berlin 2008 – scientific programme
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HL: Fachverband Halbleiterphysik
HL 45: GaN devices
HL 45.2: Talk
Thursday, February 28, 2008, 09:45–10:00, EW 202
External field dependent spatial resolved PL spectroscopy on InGaN/GaN heterostructures — •Clemens Vierheilig1, Harald Braun1, Ulrich T. Schwarz1, Werner Wegscheider1, Nikolaus Gmeinwieser2, Ansgar Laubsch2, and Berthold Hahn2 — 1NWF II - Physik, Universität Regensburg, Universitätsstraße 31, 93053 Regensburg — 2Osram Opto Semiconductors, Leibnizstraße 4, 93055 Regensburg
The optical properties of InGaN based quantum well structures are strongly affected by internal electric fields and fluctuations of the indium content. By micro-photoluminescence of InGaN LEDs with applied bias and micro-electroluminescence we study the correlation between QW emission intensity and energy, both of which fluctuate on a micrometer length scale. Particularly interesting is the characteristic dependency of this energy-intensity correlation on the applied external electric field. For a spatially resolved measurement of the tunnel barrier we also measure the laser induced photocurrent under reverse bias. Purpose of this study is to separate QW composition or width fluctuation from fluctuations of the internal fields.