Effects of Ligand on the Optical Properties of Manganese Sulphide Thin Films Prepared Using Chemical Bath Deposition (CBD) Technique

Abstract

Thin films of Manganese sulphide semiconductor material were successfully deposited on glass substrate using Chemical Bath Deposition (CBD) technique. The Films were optically characterized using PYE UNICAM SP8-100 Double Beam Spectrophotometer with uncoated glass substrate as a reference frame. The effects of various concentrations of ligand (TEA) on the optical properties of the deposited films were studied. The result shows that the absorbance was observed to decrease towards the infra-red region of electromagnetic spectrum with a value range of 17.5% -72.7%, and the film deposited at 4ml ligand concentration having a highest peak value of 72.7% at 380nm.  The transmittance property of the films was found to be moderate and increases towards the infra-red region. The deposited films exhibited poor reflectance, extinction coefficient, and imaginary part dielectric function properties with film deposited at 2ml concentration of ligand possessing high optical conductivity value of 1.08 x 10¹⁴S^-1. Refractive index and real part dielectric function of the films were observed to be also high with band gap energy of 2.80eV- 3.15eV. All these desirable properties made the semiconductor to be a good candidate for applications in photovoltaic devices.

Keywords: Ligand, semiconductor, electromagnetic spectrum, transmittance, reflectance, optical conductivity, and spectrophotometer.