Insertion of ALE grown ZnTe monomolecular films in CdTe/CdZnTe heterostructures to probe the quantum well eigenstates

A local probe, such as a localized isoelectronic perturbation, was used to measure the spatial variation of the probability densities in the first two excitonic states of a CdTe/CdZnTe quantum well (QW). One monolayer thick ZnTe planar probes were located either in the center of CdTe/CdZnTe QWs, or at one third and two third of the width of the QWs by atomic layer epitaxy which allows to control exactly both the amount of zinc incorporated and its position inside the QW width. Photoluminescence and reflectivity measurements at low temperature were used to determine the energy position and shift in energy of both the excitonic ground state e1h1 and the first excited one e2h2 when compared to a reference sample without ZnTe insertion. The results obtained are supported quantitatively by a calculation.