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

Abstract

In this study, CdS, CuS, and Ag2S 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, Ag2S, 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, Ag2S, 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/Ag2S 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.