Chemical bath synthesis of Ag₂S, CuS, and CdS nanoparticle-polymer nanocomposites: structural, linear, and nonlinear optical characteristics

Abstract

In this study, CdS, CuS, and Ag 2 S nanoparticles (NPs) were synthesized by a chemical bath procedure in the presence of polyvinyl alcohol (PVA) as a polymer stabilizer. Morphological studies followed by X-ray diffraction (XRD) and atomic force microscopy (AFM) revealed monolithic and small size NPs. The average crystalline size of CdS, Ag 2 S, and CuS nanocomposites was 18.1, 26.7, and 21.7 nm, respectively. UV-Vis absorption and photoluminescence (PL) spectra of samples showed a near-infrared region (NIR) emission peak for CuS. The bandgap of samples measured using absorption data was 3.48, 2.75, and 2.30 eV for CdS, Ag 2 S, and CuS NPs, respectively. Nonlinear optical properties, including nonlinear refractive index and nonlinear absorption of the NPs, were measured by the Z-scan technique under a 632.8 nm wavelength He-Ne CW laser. PVA/Ag 2 S nanocomposite displayed reverse saturable absorbance (RSA) and self-focusing, while PVA/CdS and PVA/CuS displayed saturable absorbance and self-defocusing behavior under the chemical bath procedure synthesis.