Effect of Manganese Percentage Doping on Optical Properties of Zinc Sulphide (ZnS) Nanofilms prepared by Electrodeposition method [ ]

Zinc sulphide nanofilms with different Mn percentage doping were prepared from aqueous solution mixture of zinc chloride, manganese chloride, sodium thiosulphate and a complexing agent triethanolamine using electrodeposition method. The experiment was carried out at room temperature, optimum deposition time and deposition voltage using acidic bath maintained at PH 3 while the Mn content in the electrolyte was varied from 3% to 23%. The x-ray diffraction pattern showed that ZnS:Mn nanocrystals have cubic structure with crystallite size of approximatrly 14.19nm. The thickness of the film samples determined by optical method were of range 46.01 – 68.99nm. With the increase of Mn doping% from 3% to 23%, the optical parameters which include absorbance varies from 0,02 to 0,65; transmittance from 0.90 to 0.52; reflectance 0.27 to zero; refractive index 1.14 to 1.02. The band gap energy of ZnS:Mn film with 8% Mn doping was found to be 2.30eV and is lower than 3.65eV reported for undoped ZnS. The results showed that Mn percentage doping has effect on optical properties of ZnS nanofilms. Such nanofilms could be suitable for wide range of applications in thin films solar cells fabrications, luminescence and optoelectronic devices.