Self-organized formation and photoluminescence of Cd1−xMnxTe quantum dots grown on ZnTe by atomic layer epitaxy

Abstract

Self-organized quantum dots (QDs) of Cd1−xMnxTe were grown on the ZnTe(100) surface by atomic layer epitaxy. Atomic force microscope measurement on the surface of a 3.5-ML-thick Cd1−xMnxTe layer revealed dot formation in a high density of the order of 1010–1011 cm−2 when the Mn composition x was less than 10%. The typical dot size was given approximately by 20 nm in diameter and 2 nm in height. In photoluminescence (PL) measurements on the capped QDs, the excitonic emissions from the QDs were observed at 2.16–2.27 eV in the range of Mn composition x=0%–10%. The PL spectra from Cd1−xMnxTe QDs with x=0.6%–10.2% consisted of two lines separated by about 20 meV. The dependence of the PL energies on the Mn composition and the Zeeman shift were compared with the calculation.