Lead sulfide/polymer nanocomposite morphological and optical characteristics controlled under metal impurity doping

Doping metal impurities is a solution for obtaining new properties for semiconductor nanocomposites. It provides a tool for structural and optical characteristics controlling for the material.  PVA/PbS nanoparticles synthesized by chemical bath route in the presence of PVA polymer as colloidal stabilizer Sn and Ag ions injected in material as impurities. Samples investigated by XRD and TEM for morphology and structural studying, which were in agreement with each other. Optical spectroscopy of nanocomposites studied by Uv-Vis (300-900 nm) range absorption spectra and by using tach relation bandgap of samples was measured that was obviously a semiconductor (around 2.3 -2.8 eV). Studying followed by photoluminescence spectroscopy (PL), we saw in this case for both impurities PL quenched by doping. Nonlinear measurements were done by the Z-scan technique with a He-Ne CW laser by 632.8 nm wavelength. For nonlinear refractive index n₂ and nonlinear absorption β, self-focusing and saturable absorber attributes were observed respectively. n₂ and β were from the order of 10^-9  and 10^-3 respectively.