Facile hydrothermal synthesis of Mn doped ZnS nanocrystals and luminescence properties investigations

Mn doped ZnS is considered as one of the most important group II-VI semiconductors in the last two decades since its good character of stable emission, heavy metal free and environmental friendly. A facile, effective and green hydrothermal protocol was reported to synthesize Mn doped ZnS nanocrystals. The obtained nanocrystals are pure β-phase, spherical, mono-dispersed and narrow in size distribution. Besides the well-known Mn: 4T1-6A1 energy transition, photoluminescence (PL) spectra indicated that the transition also occurred between the surface-defect state to the Mn 4T1 state, leading to the emission changing from green to orange. By investigating the steady state and time-resolved PL spectra, a novel energy transition and transfer mechanism is established.