Structural, linear/nonlinear optical, and electrical characteristics of polyvinyl chloride doped with non-stoichiometric nano cadmium sulfide

In this work, it was proposed to introduce non-stoichiometric nano cadmium sulfide (CdS_1-x) nanoparticles into polyvinyl chloride (PVC) polymer using simple, environmentally friendly and low-cost techniques. Undoped and doped PVC polymers with non-stoichiometric CdS_1-x were formed using casting and thermolysis procedures. Rietveld refinement was applied to identify the phases formed and microstructure parameters in non-stoichiometric CdS_1-x. Different techniques were used to investigate the structure, morphology, optical properties and dielectric of polymer films. The direct and indirect optical band gap (E_g) values of the undoped PVC film are 5.63 eV and (5.22, 4.49, 3.51) eV. As the sulfur concentration in the nanofiller increased to 97%, the direct and indirect E_g values of the CdS_1-x doped polymers decreased to (5.21, 4.07, 2.44) eV and (4.18, 2.3, 2.03) eV, respectively. The optical dielectric constant and optical conductivity reached their maximum values as the amount of sulfur reached 97% in CdS_1-x. Doped polymers are effective materials against UVA, UVB, and UVC spectra and work very well as solar cell absorber materials. The CIE 1931 chromaticity diagram revealed that PVC shifted from blue color to green-yellow and yellow-orange regions under excitation wavelengths of 317 and 380 nm, respectively. The electrical dielectric constant reached its maximum value when the sulfur content of the nanofiller reached 95%. AC conductivity has its maximum value when PVC is loaded with CdS_0.9. The manageable optical and electrical features show that PVC/CdS_1-x polymers could be potential optical materials in the development of futuristic flexible-type optoelectronic devices.