Performances of effective medium model in interpreting optical properties of polyvinylcarbazole:ZnSe nanocomposites

Abstract

The effective medium model is applied to investigate the optical properties of hybrid nanocomposite layers of Polyvinylcarbazole (PVK) and nanoparticles of Zinc Selenide (ZnSe). Thin films of PVK:ZnSe nanocomposites show a porous microstructure with pore diameters of 500 nm. Numerical calculations led to the determination of optical constants such as the refractive index n, the extinction coefficient k, the dielectric permittivity ε, and absorption coefficient α. Using common theoretical models, we have determined the Cauchy parameters of the refractive index, namely, static εs and lattice ε∞ dielectric constants as well as the plasma frequency ωp, carrier density to effective mass ratio Nme*, and the optical conductivity σoc. We show that the optical band gap energy Eg of the nanocomposite structure decreases slightly upon the increase of the nanoparticles volume fraction and is in good agreement with the Vegard law.

Effect of nanocrystals concentration on optical and luminescent properties of PVK:ZnSe nanocomposites

“…The incorporation of small amount of ZnSe nanoparticles (10 wt.%) resulted in a red shift and decrease in steepness of absorption edge (304 nm) along with an increase in the absorbance of the bump in PVK:ZnSe nanocomposites. Similar values of the optical gap and red shift in the optical gap have been reported for the PVK:ZnSe composite films [25]. The anomalous variation in the absorption coefficient below the absorption edge can be ascribed to the combined effect of light scattering from the nanoparticles and their aggregated structures formed in the nanocomposite films.…”

Characteristics of Poly(vinyl Alcohol) (PVA) Based Composites Integrated with Green Synthesized Al3+-Metal Complex: Structural, Optical, and Localized Density of State Analysis

“…An increase in E d and a decrease in E o values with increasing the concentration of the Al 3+ complex solution were observed. There is a relation of E o with the optical band gap ( E g ) [ 84 ]. For the present films, empirically, the E o values are equal to the direct E g (i.e., E o ≈ E g ), as shown in Table 4 .…”

Dielectric properties of poly-(3-octylthiophene) thin films mixed with oleic acid capped cadmium selenide nanoparticles

“…These NPs may affect the formation of the polymer percolating network. [59][60][61] As observed in the micrographs, the OA-capped CdSe NPs are well dispersed in the polymer matrix. This results in the augmentation of the polymer/NPs interface leading to an increase in the probability of the exciton dissociation.…”