Photoluminescence properties of Mn-doped ZnxCd1-xS nanocrystals synthesized via nucleation-doping strategy

Optical properties of Mn-doped ZnxCd1-xS nanocrystals were studied by steady-state and time-resolved photoluminescence (PL) spectroscopy. The doped nanocrystals with PL quantum yield up to 29% were synthesized by growing a thin ZnS layer on the MnS core and then growing a CdS layer with different thicknesses using nucleation-doping strategy. The absorption band edge of ZnxCd1-xS nanocrystals was tuned from 425 to 475 nm by growing the CdS layer with various thicknesses under different Zn/Cd molar ratios to vary the composition. The PL band of Mn-doped nanocrystals was found to originate from emissions of Mn2+ ions and defect states. (c) 2012 Elsevier B.V. All rights reserved.