Compositional, Structural, and Optical Properties of Nanocrystalline Mn Doped ZnS Thin Films Prepared by Chemical Deposition Method

ZnS:Mn thin films were deposited on quartz, Si (polycrstal), and glass substrates using a chemical deposition method in an aqueous solution containing ethylene diamine tetra acetic acid disodium salt as the complexing agent for zinc ions and thioacetamide as the sulfide source at temperatures ranging from 50 to 80 °C. ZnS:Mn thin films with thicknesses ranging from 60 to 450 nm were synthesized at various Mn2+/Zn2+ molar ratios ranging from 1 to 4. The effects of the process parameters on the properties of ZnS:Mn films were investigated. The films were characterized by ICP-AES, XPS, XRD, and photoluminescence (PL) spectroscopy. The results showed that the deposition time, temperature and Mn doping concentration can affect the composition, surface morphology, crystallinity, thickness, grain size, and hence the photoluminescence and transmission spectra of the films. UV-Vis transmission spectroscopy showed that the prepared films were highly transparent (> 80%) in the visible region. X-ray diffraction showed that the films consisted of small ZnS:Mn nanocrystalites, 3.0-4.7 nm in size, showing quantum size effects.

Keywords:

Nanostructures , ZnS:Mn Thin films , Chemical Deposition