Optical Spectroscopy On Metastable Zincblende Mns/Znse Heterostructures

We have grown MnS/ZnSe heterostructures by molecular beam epitaxy on (100) GaAs substrates. The thickness of the MnS layers ranges from about I to 8 run. We studied the optical properties of the heterostructures using time-resolved photoluminescence spectroscopy with time scales from microseconds to milliseconds at low temperature. The photoluminescence is dominated by the T-4(1) to (6)A(1) internal transition of the Mn2+ (3d(5)) cations at 590 nm. The decay times of the internal luminescence show a weak dependence only on the MnS layer thickness and do not vary when using different excitation energies, i.e. 355 nm (3.49 eV) exciting above the ZnSe band gap or 532 nm (2.33 eV) excitation exciting directly into the Mn 3d(5) absorption but below the ZnSe and MiS band gaps.