Excitons as a probe of interface morphology in Cd Zn/SerZnSe heterostructures

We present studies of the excitonic spectrum in superlattices SLs. of CdSe insertions in a ZnSe matrix aimed at elucidating the CdSerZnSe interface morphology. The experimental photoluminescence excitation spectra are compared with the results of variational exciton calculations performed within the effective mass approximation. The shape of the average vertical along the SL growth axis.distribution of CdSe within each insertion, used in the calculations, was obtained from a theoretical simulation of X-ray diffraction XRD.rocking curves measured in the same samples. The results indicate that the thinnest layers are graded composition ZnCdSe quantum wells QWs., generally homogeneous in the layer planes, whereas flat islands enriched by Cd appear at the CdSe nominal thickness larger than 0.5–0.6 monolayer ML.. q2000 Elsevier Science B.V. All rights reserved