In situ synthesis and third-order nonlinear optical properties of CdS/PVP nanocomposite films

Cadmium sulfide (CdS) nanocrystals were in situ grown in a polyvinylpyrrolidone (PVP) matrix at room temperature using cadmium nitrate and thioacetamide as the cadmium and sulfur sources, respectively. It was found that the growth of CdS nanocrystals in the PVP matrix was well controlled and the mass concentration of CdS could be up to 18.2 wt% without the formation of large precipitates. The third-order nonlinear optical properties of the composite films were studied at 532 nm in the nanosecond regime by using the Z-scan technique. The results showed that the CdS/PVP nanocomposite film has a promising optical property exhibited by a nonlinear optical refractive index and an absorption coefficient of -1.65 × 10^-11 cm² W^-1 and -4.25 × 10^-7 cm W^-1, respectively. The flexible processing technique allows the production of optical devices with various shapes.