The current paper presents the advantages of the addition of CdSe nanoparticles (NPs) with different ratio (0,
0.25, 0.5, 0.75, 1.0, 1.25 and 1.5%) on opto-electrical properties of Epoxy resin [ER]. The organometallic method
was used for preparing CdSe (NPs) in epoxy matrix solution. The morphology of the obtained nanocomposites
(NCs) was characterized in terms of X-Ray diffraction, scanning electron microscope (SEM), Energy -dispersive X-
ray spectroscopy (EDX), optical and dielectric properties. The UV–Visible absorption spectra for (NCs) were
collected in the wavelength range (250–700 nm) and were analyzed. The absorption coefficient (
α), optical
energy gap (E
), and refractive index (n) showed a clear dependence on the CdSe NPs concentration. Increasing
the ratio of CdSe NPs led to the increase of the values of the absorption coefficient (
α). Moreover, the results also
demonstrate that the value of the direct optical band energy for [ER] was decreased from 3.40 eV to 2.69 eV with
increasing the CdSe (NPs) concentration from 0.25% to 1.50% in the [ER]. It was also observed that the optical
energy gap (E
g
g
) is correlated with the optical electronegativity (Δχ
) and is affected by the increase of CdSe
NPs ratio as well. The refractive index (n), the dielectric constant (
ε) and optical dielectric constants (ε
opt
)
increased with the increase in CdSe NPs content. Furthermore, the optical conductivity (
σ
), increases with the
increase CdSe NPs content. Finally, the variation of the electronic polarizability (
α
e
opt
), the dielectric susceptibility
(
χ
e
), transmission coefficient (T) and reflection loss (R
) with the increase of CdSe NPs ratio in [ER] were
analyzed. In this work we highlight the significance of the interrelations between the above defined parameters,
which were successfully predicting their effect on the performance of [ER] upon the addition of CdSe NPs.