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HL: Fachverband Halbleiterphysik

HL 45: GaN devices

HL 45.2: Vortrag

Donnerstag, 28. Februar 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.