Study of the optical properties of crystal violet doped PVA

In this work, optical properties including absorption coefficient (α), linear refractive index (n) as well as the energy gap (Eg) of crystal violet dye was estimated in two phases. The first phase: when the dye was dissolved in water at different concentrations (1 × 10-1, 1 × 10-2, 1 × 10-3, 1 × 10-4, 1 × 10-5ml). The second phase is the deposition of polyvinyl alcohol for different thicknesses (2, 4, 6, 8 and 10 µm) and with fixed concentration (1 × 10-3 ml) as thin films. It was found that the linear optical properties increased with increasing thicknesses while the energy gap is increasing from 3.9 to around 4.1 eV with increasing CV concentrations resulting from the indirect transitions.