Mechanism of Radiative Mn$\text{}^{2+}$ Intra-Shell Recombination in Bulk ZnMnS

Origin of a fast component of the photoluminescence decay of Mn$\text{}^{2+}$ intra-shell $\text{}^{4}$T$\text{}_{1}$ → $\text{}^{6}$A$\text{}_{1}$ transition is discussed based on the results of photoluminescence, photoluminescence kinetics and optically detected magnetic resonance experiments performed for bulk ZnMnS samples with about 1% Mn fraction. It is demonstrated that a fast component of the photoluminescence decay, reported previously for quantum dot structure and related to quantum confinement effects, is also observed in bulk samples and is related by us to very efficient spin cross-relaxation effects.