Synthesis and characterization of nanostructured Mn-doped ZnS thin films and nanoparticles

摘要

Nanocrystalline ZnS:Mn~(2+) thin films and powders were prepared by chemical bath deposition (CBD) at 85℃ for different concentration of Mn ions in bath solutions (Mn molar fraction, x = 0.0, 0.01, 0.02, 0.05, 0.1, 0.2 and 0.5). Produced nanocrystalline films and powders were characterized using X-ray diffraction (XRD), differential thermal analysis (DTA), scanning electron microscopy (SEM) and photolu-minescence measurements. XRD patterns for Mn~(2+) doped and undoped ZnS powders showed broad peaks corresponding to ZnS exhibiting a mixture of cubic and hexagonal structures. Size of nanocrystallites was estimated to be 4 nm using Scherrer's equation. The DTA analyses evidenced the development of the oxide phase from ZnS nanocrystals at lower temperature than for bulk micron size particles. SEM observations showed the presence of nanocrystallites forming spherical aggregates of around 500 nm in diameter. Photoluminescence measurements reveal a strong emission peak at 580 nm which is characteristic emission peak of Mn~(2+) d-d transition confirming the actual incorporation of Mn~(2+) into ZnS framework.