Optical properties enhancement of hybrid nanocomposites thin films based on P3HT matrix and ZnO@SiO2 core-shell nanoparticles

The synthesis of ZnO@SiO2 core-shell nanoparticles (NPs), their incorporation in the P3HT polymer matrix and the optoelectronic properties of the composite layer are reported. The ZnO@SiO2 NPs were synthesized by wet chemical reaction and incorporated in the polymer matrix at different weight ratios of 20, 40 and 60%. The photoluminescence spectra were used to investigate the optical properties of the samples as well as the transfer mechanism of the excitons. An exciton quenching rate constant gamma of 3.10(-11) cm(3) s(-1) is determined using the Stern-Volmer equation. The measurements of transmittance and reflectance were used to obtain the optoelectronic properties of the composite specimens. The possibility to control the refractive index (n) of the P3HT:ZnO@SiO2 composite layer by changing the NPs concentration and the improvement of its semiconducting behavior are reported. Tauc and Wemple-Didomenico models are used to analyze the experimental data and obtain the energy gap of the P3HT:ZnO@SiO2 nanocomposite thin films. The dielectric constant, frequency of plasma and the ratio of carrier density to the effective mass N/m(e)(1) were calculated by Drude - Lorentz model. The determination of these parameters and their dependence on the density of ZnO@SiO(2)NPs and the excitation wavelength are believed to aid our understanding of the behavior of the P3HT:ZnO@SiO2 nanocomposite layer.