Influence of Mn2+ Magnetic Ions on the Properties of Cd1 – xMnxS Thin Films Synthesized by Chemical Bath Deposition

Abstract

II-VI semiconductor based ternary CdMnS compound material has received more attention due to its wide area of applications in semiconductor technology. Cd 1 – x Mn x S ( x  0, 0.2, 0.4, 0.6, 0.8 and 1.0) thin films were successfully prepared by chemical bath deposition technique on non-conducting glass substrates. Thin films were deposited at a bath temperature of 80  C and pH  11 by using the chemical bath reaction of cadmium chloride (CdCl 2 ) and manganese chloride (MnCl 2 ) with thiourea (NH 4 ) 2 S in an aqueous solution. Further, the prepared samples were characterized by UV-visible spectroscopy, photoluminescence, XRD, SEM and EDAX to study the optical, structural, surface, and chemical properties. Effect of Mn 2+ ions on the film thickness of Cd 1 – x Mn x S films was investigated using weight difference technique. The film thickness of Cd 1 – x Mn x S films decreases as Mn 2+ ions increase in the bath solution. The polycrystalline nature with hexagonal and cubic structures of the as-deposited films was confirmed by XRD. The band gap value of the deposited films was observed to increase with increasing Mn 2+ ion concentration, this might be ascribed to the fact that Cd atom was substituted by Mn atom in the CdS structure. EDAX analysis confirmed the deposition of Cd, Mn and S elements in the films. Photoluminescence spectra of Cd 1 – x Mn x S with different values of the composition parameter x exhibited two emission peaks with different intensities. The measurement of the electrical resistivity of Cd 1 – x Mn x S films was performed at room temperature using two probe methods. The variation in electrical resistivity values with compositional parameters was discussed based on deposition parameters. The investigated polycrystalline Cd 1 – x Mn x S thin films show promising technological applications in semiconductor industry.