Linear and Non-linear optical parameters of Copper Chloride doped Poly (Vinyl Alcohol) for Optoelectronic Applications

Poly (Vinyl Alcohol)/Copper Chloride (PVA/CuCl2) composite samples have been prepared using casting method with 1, 10 and 20 wt% of CuCl2. UV-Vis spectrum of these composites is investigated in the range of 200-900 nm. The absorption spectrum of PVA showed an absorption band at 278.18 nm and a small shoulder at 313.09 nm and are assigned to π- π*and nπ*transition, respectively. On the other hand, the spectra of the PVA/CuCl2 composite samples showed a surface Plasmon resonance (SPR) band in the visible band at 778.07 nm. Moreover, it is observed that, the absorption edge of composite samples is red shifted. Also, pure PVA showed an indirect and direct optical energy gap in the range of 4.71 and 5.08 eV, which decreased to 3.48 and 3.92 eV after CuCl2 incorporation, indicating a structural defect in the matrix of PVA. It was also observed that nonlinear optical parameters such as third-order nonlinear optical sensitivity (χ(3 ) as well as the nonlinearrefractive index (n2) are influenced by CuCl2 incorporation and their values increased with increasing Cu chloride content. These results are very encouraging for possible applications in nonlinear optical (NLO) devices. The optical dielectric constant (ϵ'), dielectric loss (ϵ') and photoconductivity have been investigated.