Molecular beam epitaxial growth of ultrathin CdTe–CdMnTe quantum wells and their characterization

Abstract

We report the growth and optical characterization of CdTe/CdMnTe single quantum wells with well thicknesses ranging from 60 down to 6 Å. The single quantum wells were grown by standard molecular beam epitaxy without growth interruption and investigated by reflection, photoluminescence (PL), and excitation PL. All structures including the 6-Å-thick quantum well exhibit extraordinarily narrow photoluminescence lines. From an analysis of linewidth and Stokes shift of the photoluminescence lines informations on the structure of the CdTe/CdMnTe interfaces are derived. The good quality of those structures made it possible to identify for the first time recombination of two-dimensional free exciton magnetic polarons.

Optically Detected Cyclotron Resonance Studies of CdMnTe/CdTe Multiquantum Wells and CdMgTe/CdMnTe Superlattices

“…This band, attributed to the donor bound exciton (DBE) emission, shifts towards lower energies by about 0.6 meV during the time of the decay. The present results confirm the kinetics measurements recently performed on similar stuctures [2], but differ considerably from those observed for III-V QW stuctures, where a larger shift of the exciton bands is observed during the decay [3]. The PL decay experiments indicate that the high energy PL band has properties of a localized exciton (LE) emission, and that the LE is trapped by potential fluctuations in the QW.…”

“…1b and c. A positive component was observed on the high energy part of ODCR-PL spectrum of the 60 Á QW, this indicates that LEs can be turned into free excitons (FEs) by interaction with hot carriers. A small shift between LE and FE PL bands confirms previous estimations that the fluctuations of the QW width are restricted to 1 monolayer [2]. For the 100 Α QW the higher energy part of the PL spectum is quenched, whereas the lower is enhanced due to the difference in carrier localization energy (exciton binding energy) for QW regions of different average width.…”

Growth evolution of surface nanowires and large anisotropy of conductivity on MgZnO/ZnO quantum wells based on M-nonpolar (10−10) ZnO

“…PL lines at 3.304 and 3.341 eV for E Ќ c and E ʈ c were attributed to A-and C-exciton transitions, respectively. 30 From Fig. The energy separation ͑⌬E͒ between emission peaks at E Ќ c and E ʈ c polarizations was 37 meV, a value close to the theoretical value ͑40 meV͒ when the valence band ordering is considered.…”

Temperature Study of Photoluminescence from Deep CdTe/Cd1-xMnxTe Quantum Wells

“…The line width of the observed luminescence at 10 K ranged from 2 meV (for 100 A wells) through 7 meV (for 40 A wellS) to 15 meV (for 200 A wells). The line width is comparable to that seen in samples obtained in other laboratories [3]. In the case of 100 A, 60 A and 40 A quantum wells in all our samples a doublet structure of the luminescence lines could be resolved with the distance between two features being of the order of 3 meV.…”