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HL: Halbleiterphysik

HL 25: Heterostrukturen II

HL 25.1: Vortrag

Dienstag, 9. März 2004, 18:00–18:15, H14

Band offset determination of InGaAsN quantum well structures employing surface photovoltage — •Massimo Galluppi, Gheorghe Dumitras, Lutz Geelhaar, and Henning Riechert — Infineon Technologies, Corporate Research Photonics, 81730 Munich, Germany

The band offset of semiconductor quantum well (QW) structures is one of the most important parameters one needs to know in order to predict the properties of electronic or optoelectronic devices based on such structures. The here presented method is based on surface photovoltage (SPV) experiments [1].The band offset and the band alignment result directly from examining the SPV spectrum. In contrast to conventional techniques, this method has the advantage that no fitting procedures are needed and that the exact knowledge of the potential across the QW is not required.

The method was employed to investigate InGaAs and InGaAsN single QW structures. A good accordance with the results predicted by theory and measured by conventional experimental techniques was found. In addition, the dependence of the band offsets on the indium and on the nitrogen concentration was studied. While the indium concentration affects both the conduction and the valence band offsets, the nitrogen concentration changes only the conduction band offset.

[1] Gh. Dumitras et al., PRB 66, 205324 (2002); Gh. Dumitras et al., JAP 94, 3955 (2003).