Numéro
Le Journal de Physique IV
Volume 03, Numéro C5, Octobre 1993
Third International Conference on Optics of Excitons in Confined
Page(s) C5-99 - C5-106
DOI http://dx.doi.org/10.1051/jp4:1993518
Third International Conference on Optics of Excitons in Confined

Le Journal de Physique IV 03 (1993) C5-99-C5-106

DOI: 10.1051/jp4:1993518

Morphology of InGaAs/InP QWs : from excitonic spectroscopy to HR-TEM analyses

J. CAMASSEL1, S. JUILLAGUET1, R. SCHWEDLER2, K. WOLTER2, F.H. BAUMANN3, K. LEO2 and J.P. LAURENTI4

1  GES, Université de Montpellier II, 34095 Montpellier cedex 5, France
2  Institute of Semiconductor Electronics II, RWTH, 5100 Aachen, Germany
3  AT&T Bell Labs., Holmdel, NJ 07733, U.S.A.
4  CLOES-SUPELEC, Université de Metz, 57078 Metz cedex 3, France


Abstract
We report on the non-squared composition profiles of three series of thin (Lz[MATH]30Å) InGaAs/InP quantum wells grown with interruption sequences at, both, the lower and the upper interfaces. First is a series of LM (lattice matched) samples with nominal thicknesses ranging from 0 to 8 monolayers. Second is a series of samples with a constant thickness of 5 monolayers and gallium compositions ranging from 0.13 to 0.73. Third are two samples with thickness Lz=30Å and gallium compositions x=0.47 (LM) and x=0.73 (gallium rich). Comparing spectrometric data collected at 2 K with high-resolution transmission electron microscope (HR-TEM) pictures, we find that the lower interface morphology (InP/InGaAs) can be easily probed from excitonic absorption and luminescence spectra. Nothing similar is found for the higher interface (InGaAs/InP), even if a considerable amount of interface roughness is resolved from HR-TEM. We show that this upper interface roughness originates from unperfected 2-dimensional growth kinetics of InGaAs.



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