Effect of Manganese Doping Percentage on Band Gap Energy of Cadmium Sulphide (CdS) Nanofilms Prepared by Electrodeposition Method

Cadmium sulphide (CdS) nanofilms with different Mn percentage doping were prepared by electrodeposition method at room temperature using aqueous solution of cadmium chloride, manganese chloride, sodium thiosulphate and triethanolamine as the complexing agent,. The XRD studies showed that the Mn doped CdS nanofilms have cubic structure with crystallite sizes of range 0.288 to 2.739nm. The thickness of the films determined by optical method were of range 2.04nm to 20.82nm. The band gap energy of CdS nanofilms increased with the increasing of Mn percentage doping and their values of range 2.02eV to 2.35 eV were slightly lower than 2.42eV, the literature value for bulk CdS. The observed decrease in band gap energy values of CdS films with different Mn percentage doping may be due to spd exchange interaction between the band electrons and localized d- electrons of Mn ions substituting Cd+2 ions. Such Mn doped CdS films could be suitable for applications in thin films solar cells fabrications, photo-thermal and optoelectronic devices.