Enhancement of Mn luminescence in ZnS:Mn multi-quantum-well structures

Abstract

Multi-quantum-well structures of ZnS:Mn-SiO2 were prepared by sequential rf sputtering. The thickness of ZnS:Mn layers differed from 2 to 10 nm, while that of SiO2 layers was 40 nm. It was shown that the efficiency of Mn luminescence is considerably larger in samples with ZnS:Mn thickness of 2 nm compared to samples with thicker layers. A possible mechanism to explain this effect is the formation of quantum-dot-like features in the low thickness layers, resulting in regions with higher local Mn concentration, hence higher luminescence efficiency.