Optical linearity and bandgap analysis of Erythrosine B doped in polyvinyl alcohol films

Polyvinyl alcohol (PVA) has utilized in various fields of industry. PVA has been chosen as a host matrix and then doped with Erythrosine B dye (EB) with different concentrations of EB by using casting procedure. The linear optical properties have been studied and it found that the refractive index of PVA that contains 4 wt % of EB dye decreased by 18% with respect to that obtained for the pure sample. Also, the energy gap of PVA doped samples was studied and found three kinds of interband. The calculated nonlinear properties for pure and doped PVA samples were investigated. The calculated values of the third-order susceptibility, χ(3), and nonlinear refractive index, n2, are decreased by EB doped and the sample doped by 4 wt % of EB has the lowest value of χ(3) and n2. The obtained values of the refractive index candidate our synthesized materials to participate in light-emitting diodes and images sensor.