Growth evolution and magneto-optical characteristics of self-assembled ZnTe/ZnMnSe quantum dots

The growth evolution and the magneto-optical characteristics of the self-assembled single-layer ZnTe/ZnMnSe quantum dots grown by molecular beam epitaxy were investigated. As the ZnTe coverage is above 2.0 monolayers, a Stranski–Krastanov growth process is observed with a significantly increased dot density on top of two-dimensional plateaus. As the coverage exceeds 2.7 monolayers, ripened dots dominate instead. Furthermore, a saturated degree of circular polarization of 76% at applied magnetic field of 4 T and the formation of magnetic polarons with a formation time of 7.4 ns were demonstrated.

► Size of self-assembled ZnTe QD on ZnMnSe was controlled by tuning coverage. ► Stranski–Krastanov and ripened process occur as coverage exceeds 2.0 and 2.7 ML, respectively. ► QD system shows a strong degree of polarization and the formation of magnetic polarons.